Acne is a common skin condition that occurs when hair follicles become clogged with oil and dead skin cells. It often appears on the face, forehead, chest, back, and shoulders. Acne can range from mild (whiteheads and blackheads) to severe (cysts and nodules). While it's most common in teenagers, acne can affect people of all ages. It's generally not a serious health threat, but it can be persistent, bothersome, and cause scarring.
An abscess is a localized collection of pus surrounded by inflamed tissue. It can occur anywhere in the body but is most common on the skin, in the mouth, or in internal organs. Abscesses are typically caused by bacterial infections and are characterized by pain, swelling, redness, and warmth.
Acid reflux, also known as gastroesophageal reflux (GER), occurs when stomach acid frequently flows back into the esophagus, the tube connecting your mouth and stomach. This backwash (acid reflux) can irritate the lining of your esophagus. Many people experience acid reflux occasionally, but when it becomes chronic and troublesome, it's diagnosed as gastroesophageal reflux disease (GERD).
Heartburn (a burning sensation in the chest, usually after eating, which might be worse at night)
Regurgitation (the sensation of acid or food coming back up into the throat or mouth)
Sour taste in the mouth
Bloating
Nausea
Difficulty swallowing (dysphagia)
Chronic cough
Laryngitis (hoarseness)
Feeling of a lump in the throat
Acidemia refers to a condition where the blood pH is abnormally low, meaning the blood is too acidic. It's a metabolic disturbance, often indicating an underlying health problem. It is not a disease in itself, but rather a symptom or manifestation of other conditions. There are different types of acidemia, depending on the cause, such as metabolic acidemia, respiratory acidemia, and lactic acidemia.
Acne is a common skin condition that occurs when hair follicles become clogged with oil and dead skin cells. It often appears on the face, forehead, chest, back, and shoulders. It ranges in severity from mild blackheads and whiteheads to inflamed pimples, cysts, and nodules. It's most common in teenagers and young adults, but it can affect people of all ages.
Acquired Immunodeficiency Syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the Human Immunodeficiency Virus (HIV). HIV damages the immune system, interfering with the body's ability to fight off infections and diseases. AIDS is the most severe stage of HIV infection. There is no cure for HIV/AIDS, but medications can control the virus and prevent progression of the disease.
Acrocyanosis is a persistent, painless, symmetrical cyanosis (bluish discoloration) of the extremities, most commonly affecting the hands and feet. It's usually caused by small blood vessel spasms, reducing blood flow to the skin. It's generally considered a benign condition, meaning it's not usually associated with any underlying serious health issues.
Acromegaly is a hormonal disorder that develops when your pituitary gland produces too much growth hormone (GH) during adulthood. When this happens, your bones increase in size. Usually affecting the hands, feet, and face. Acromegaly is a slowly progressing disease that can result in serious illness and premature death if not treated.
Actinomycosis is a rare, chronic, granulomatous bacterial infection caused by
Actinomyces
bacteria, most commonly
Actinomyces israelii
. These bacteria are normally found in the mouth and throat of humans and animals and are usually harmless. However, when these bacteria enter traumatized tissue, such as after surgery, injury, or dental procedures, they can cause infection. Actinomycosis is characterized by the formation of abscesses that often drain pus containing "sulfur granules" (actually bacterial colonies). It can affect various parts of the body, including the jaw (cervicofacial), chest (thoracic), abdomen, and pelvic area.
Acute bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. This inflammation causes coughing, often with mucus, and can be accompanied by other cold-like symptoms. It is usually caused by a viral infection, similar to those that cause the common cold or the flu. While uncomfortable, acute bronchitis typically resolves on its own within a few weeks.
Acute Kidney Injury (AKI), formerly known as acute renal failure, is a sudden decrease in kidney function that occurs over a short period of time (hours to days). This leads to a buildup of waste products in the blood and makes it difficult for the kidneys to maintain fluid and electrolyte balance. AKI can range in severity from mild kidney dysfunction to complete kidney failure. It is often reversible if detected and treated promptly.
Acute liver failure (ALF) is a rare condition characterized by the rapid loss of liver function that occurs in a person with no pre-existing liver disease. It develops quickly, often within days or weeks. ALF is a life-threatening emergency requiring immediate medical attention and potentially liver transplantation. The liver normally filters toxins, helps digest food, and stores energy, among other crucial functions. When it fails abruptly, it can lead to serious complications affecting other organs.
Acute Lymphoblastic Leukemia (ALL), also known as Acute Lymphocytic Leukemia, is a type of cancer of the blood and bone marrow that affects the white blood cells, specifically the lymphocytes. It is characterized by the rapid production of immature lymphocytes, called lymphoblasts or leukemic blasts, which crowd out healthy blood cells and prevent them from functioning properly. ALL progresses quickly and requires immediate treatment. It is the most common type of cancer in children, but adults can also develop ALL.
Acute Myeloid Leukemia (AML) is a cancer of the blood and bone marrow characterized by the rapid growth of abnormal white blood cells (myeloblasts) that accumulate in the bone marrow and interfere with the production of normal blood cells. It is an aggressive type of leukemia that requires prompt treatment. AML can affect people of all ages, but it is more common in older adults.
Acute pancreatitis is a sudden inflammation of the pancreas. The pancreas is a gland located behind the stomach that produces enzymes to help with digestion and hormones to regulate blood sugar. In acute pancreatitis, these enzymes become activated while still in the pancreas, causing it to digest itself. This can lead to severe pain, organ damage, and in some cases, death. It's usually a short-term illness but can be life-threatening.
Acute Respiratory Distress Syndrome (ARDS) is a severe lung condition characterized by widespread inflammation and fluid buildup in the air sacs (alveoli) of the lungs. This fluid prevents the lungs from properly filling with air, reducing the amount of oxygen reaching the bloodstream. ARDS typically occurs as a complication of another underlying illness or injury. It's a medical emergency requiring immediate treatment, often in an intensive care unit (ICU). The condition can be life-threatening.
Symptoms of Addison's disease can develop slowly, often over several months. Common symptoms include:
Extreme fatigue
Weight loss and decreased appetite
Skin darkening (hyperpigmentation), particularly in skin creases, scars, and gums
Low blood pressure, even fainting
Salt craving
Muscle weakness
Nausea, vomiting, or abdominal pain
Diarrhea
Irritability
Depression
Body hair loss
Hypoglycemia (low blood sugar)
Adenoiditis is the inflammation or infection of the adenoids. The adenoids are a patch of tissue located in the back of the nasal passage. Like tonsils, adenoids help to trap germs and create antibodies to fight infection. However, sometimes the adenoids themselves become infected. Adenoiditis is more common in children than adults because adenoids typically shrink during adolescence.
An adenoma is a benign (non-cancerous) tumor that originates in glandular tissue. Glandular tissue is found in many parts of the body, so adenomas can occur in various locations, such as the colon, pituitary gland, thyroid, and adrenal glands. While adenomas are not cancerous, some types can potentially progress to cancer if left untreated. The specific characteristics, symptoms, and treatment options vary greatly depending on the location and type of adenoma.
Adrenal fatigue, also known as adrenal insufficiency, is a condition where the adrenal glands don't produce enough cortisol, a hormone essential for regulating stress response, metabolism, and other vital functions. It's a controversial diagnosis, with some medical professionals not recognizing it as a distinct medical entity. The term "adrenal fatigue" is often used to describe a collection of nonspecific symptoms believed to result from chronic stress.
Adrenocortical carcinoma (ACC) is a rare cancer that begins in the adrenal cortex, the outer layer of the adrenal glands. These glands, located on top of the kidneys, produce essential hormones that regulate metabolism, immune system, blood pressure, and response to stress. ACC can be functional, meaning it produces excess hormones, leading to various symptoms, or non-functional, producing no excess hormones. It is an aggressive cancer that can spread to other parts of the body.
Adult Still's Disease (ASD) is a rare systemic inflammatory disorder of unknown cause that primarily affects adults. It is characterized by a triad of symptoms: high spiking fevers, a salmon-colored rash, and joint pain (arthritis). The disease can manifest as a single episode or can become chronic, with persistent joint inflammation and other complications. ASD is classified as an autoinflammatory disease, meaning the body's immune system attacks its own tissues without a clear external trigger.
Aerophagia, also known as air swallowing, is the unintentional or habitual swallowing of excessive amounts of air. While everyone swallows small amounts of air when eating and drinking, individuals with aerophagia swallow significantly more. This excess air accumulates in the stomach and intestines, leading to uncomfortable symptoms.
Blurred vision
Difficulty recognizing faces
A blurry or blind spot in the center of your vision
Straight lines appearing wavy or distorted
Reduced central vision in one or both eyes
Needing more light for reading or other close-up work
Difficulty adapting to low light levels
Agammaglobulinemia is a rare genetic disorder characterized by the virtual absence of antibodies (immunoglobulins) in the blood. This deficiency severely impairs the body's ability to fight off infections, making individuals with agammaglobulinemia highly susceptible to bacterial infections, particularly of the respiratory tract, sinuses, and skin. There are different forms of agammaglobulinemia, including X-linked agammaglobulinemia (XLA) and autosomal recessive agammaglobulinemia.
Agoraphobia is an anxiety disorder characterized by intense fear and avoidance of places or situations that might cause feelings of panic, entrapment, helplessness, or embarrassment. It often develops after one or more panic attacks, leading individuals to fear future attacks and avoid situations where they might occur. These situations commonly include public transportation, open spaces, enclosed spaces, crowds, or being outside of their home alone. The fear stems from the perceived difficulty in escaping or obtaining help if panic symptoms arise. Agoraphobia can significantly impact a person's ability to function in daily life, leading to social isolation and decreased quality of life.
Agranulocytosis is a severe deficiency of granulocytes, a type of white blood cell. Granulocytes (neutrophils, eosinophils, and basophils) are crucial for fighting bacterial and fungal infections. Agranulocytosis significantly weakens the immune system, making individuals highly susceptible to opportunistic infections. It can be life-threatening if left untreated.
Aicardi syndrome is a rare genetic disorder that primarily affects females. It is characterized by a partial or complete absence of the corpus callosum (the structure connecting the two hemispheres of the brain), seizures (often infantile spasms), and specific abnormalities of the retina. The severity of symptoms can vary widely among affected individuals.
AIDS-Related Complex (ARC) was a historical term used in the 1980s to describe a set of symptoms and clinical findings in individuals infected with HIV, but who had not yet developed full-blown AIDS (Acquired Immunodeficiency Syndrome). It was characterized by a weakened immune system and various opportunistic infections, but the criteria were less severe than those for a formal AIDS diagnosis. The term is no longer in common use due to advances in HIV diagnosis, treatment, and a more comprehensive understanding of HIV disease progression. Today, HIV infection is typically categorized by CD4 count and the presence of specific opportunistic infections, regardless of whether those opportunistic infections meet the old ARC criteria.
An air embolism occurs when air bubbles enter the bloodstream and block blood vessels. These bubbles can travel to the brain, heart, or lungs and cause serious complications. It's a relatively rare but potentially life-threatening condition. The severity depends on the amount of air, the rate of entry, and the location of the blockage.
Akathisia is a movement disorder characterized by a subjective feeling of inner restlessness accompanied by motor restlessness. Individuals with akathisia often feel an irresistible urge to move, and they may pace, fidget, rock, or cross and uncross their legs. It's a distressing condition that can occur as a side effect of certain medications, particularly antipsychotics. The term comes from the Greek words "a-" (meaning without) and "kathēsis" (meaning sitting).
Albinism is a rare, inherited genetic condition that reduces or completely eliminates the pigment melanin in the skin, hair, and eyes. It's characterized by a partial or complete absence of pigment. People with albinism are at increased risk of sun damage and skin cancer. Vision problems are also common.
Alcohol dependence, also known as alcohol use disorder (AUD), is a chronic relapsing brain disease characterized by compulsive alcohol seeking and use despite negative consequences. It involves a loss of control over alcohol consumption and a preoccupation with alcohol. AUD exists on a spectrum, ranging from mild to severe.
Confusion or stupor
Vomiting
Seizures
Slow or irregular breathing (less than 8 breaths per minute)
Pale or bluish skin
Low body temperature (hypothermia)
Unresponsiveness (unable to be roused)
Loss of coordination
Alcoholic hepatitis is a serious liver inflammation caused by excessive alcohol consumption over many years. It can range from mild to severe. In severe cases, it can lead to liver failure and death. The condition is often accompanied by other alcohol-related liver diseases, such as fatty liver (steatosis) and cirrhosis.
Aldosteronism (also known as hyperaldosteronism) is a condition where the adrenal glands produce too much aldosterone, a hormone that helps regulate sodium and potassium levels in the blood. This excess aldosterone leads to sodium retention and potassium loss, which can result in high blood pressure and other complications. There are two main types: primary aldosteronism, where the problem originates in the adrenal glands, and secondary aldosteronism, where another condition causes the adrenal glands to produce excess aldosterone.
Infantile: Enlarged head (macrocephaly), developmental delays, seizures, spasticity (muscle stiffness), intellectual disability.
Juvenile: Problems with coordination (ataxia), difficulty speaking and swallowing (dysarthria and dysphagia), spasticity, seizures, intellectual disability.
Adult: Bulbar symptoms (speech and swallowing difficulties), weakness in the limbs (paraparesis or quadriparesis), ataxia, seizures, involuntary movements (myoclonus), sleep disturbances.
Alkaptonuria is a rare inherited genetic disorder characterized by the body's inability to properly break down two amino acids: tyrosine and phenylalanine. This results in the accumulation of homogentisic acid (HGA) in the body, particularly in cartilage, connective tissue, and urine. Over time, this accumulation leads to various symptoms, primarily affecting the joints and spine.
Respiratory: Sneezing, runny or stuffy nose, itchy nose, postnasal drip, sore throat, coughing, wheezing, shortness of breath.
Skin: Itchy skin, hives (urticaria), eczema, rash.
Eyes: Itchy, watery, red, swollen eyes.
Digestive: Nausea, vomiting, diarrhea, abdominal pain.
Severe (Anaphylaxis): Difficulty breathing, wheezing, throat swelling, dizziness, lightheadedness, loss of consciousness.
Alopecia Areata is an autoimmune disorder that causes hair loss, typically in patches on the scalp or other parts of the body. The immune system mistakenly attacks hair follicles, leading to hair loss. The extent of hair loss varies from person to person and can range from small patches to complete baldness on the scalp (Alopecia Totalis) or entire body (Alopecia Universalis).
Alcoholism, also known as alcohol use disorder (AUD), is a chronic relapsing brain disease characterized by compulsive alcohol seeking and use despite negative consequences. It involves impaired control over alcohol consumption, preoccupation with alcohol, continued use despite problems, and withdrawal symptoms when alcohol use is stopped.
:
Genetic Counseling: Essential for families with Alport syndrome.
Regular Monitoring: Routine check-ups with a nephrologist, audiologist, and ophthalmologist are vital.
Family Screening: Other family members should be screened for Alport syndrome, especially if there is a family history of kidney disease, hearing loss, or eye abnormalities.
Personalized Management: Treatment plans should be tailored to the individual's specific symptoms and disease progression.
Support Groups: Connecting with other individuals and families affected by Alport syndrome can provide valuable support and information.
Alpha-1 Antitrypsin Deficiency (AATD) is a genetic condition that can cause lung disease, liver disease, and rarely, skin conditions. It is caused by a deficiency of the alpha-1 antitrypsin (AAT) protein, which is produced in the liver and helps protect the lungs from damage caused by enzymes like neutrophil elastase. People with AATD have lower levels of AAT in their blood, which can lead to lung damage (emphysema) and liver problems (cirrhosis).
Alzheimer's disease is a progressive neurodegenerative disorder that gradually destroys memory and thinking skills, and eventually the ability to carry out the simplest tasks. It is the most common cause of dementia, a general term for a decline in mental ability severe enough to interfere with daily life. While Alzheimer's primarily affects older adults, it is not a normal part of aging.
Reduced vision in one eye
Eye drifting inward or outward
Poor depth perception
Squinting or closing one eye
Head tilting
Abnormal results of vision screening tests
Headaches
Amaurosis fugax is a temporary loss of vision in one eye due to a lack of blood flow to the retina. It is often described as a curtain or shade coming down over the eye, affecting the field of vision. It is a warning sign that there could be a blockage in an artery leading to the eye or brain, and therefore requires immediate medical attention to prevent stroke or other serious complications.
Amebiasis, also known as amoebic dysentery, is an infection of the intestines caused by the parasite
Entamoeba histolytica
. It's spread through contaminated food or water and can range from mild symptoms to severe illness. In some cases, it can spread to other organs, such as the liver.
Amenorrhea is the absence of menstruation, typically defined as missing one or more menstrual periods. It's categorized as primary amenorrhea (never having started menstruating by age 15) or secondary amenorrhea (periods stopping for three months or more in women who previously had regular cycles, or six months or more in women with irregular cycles). Amenorrhea can be a symptom of various underlying conditions, ranging from hormonal imbalances to anatomical problems or lifestyle factors. It is not a disease itself but a symptom.
Difficulty learning new information (anterograde amnesia)
Difficulty recalling past events and previously familiar information (retrograde amnesia)
Confabulation (making up stories to fill in memory gaps)
Confusion
Disorientation
False memories
Inability to recognize familiar faces or places.
Amyloidosis is a rare disease that occurs when an abnormal protein called amyloid builds up in your organs and tissues. This buildup can affect the normal functioning of the organs and tissues. Amyloidosis can affect different organs in different people, and the severity of the disease can vary widely. There are several different types of amyloidosis, each linked to a specific protein that forms the amyloid deposits.
Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive neurodegenerative disease that affects motor neurons, the nerve cells in the brain and spinal cord that control voluntary muscle movement. As motor neurons die, the brain loses its ability to initiate and control muscle movement. This leads to muscle weakness, twitching, and atrophy. Eventually, ALS affects the muscles needed to move, speak, eat, and breathe. There is currently no cure for ALS.
An anal fissure is a small tear in the lining of the anus. It typically causes pain and bleeding during bowel movements. While often resolving on its own or with simple treatments, chronic fissures may require medical intervention.
Anaphylaxis is a severe, potentially life-threatening allergic reaction that is rapid in onset and affects multiple organ systems. It can cause a range of symptoms, including hives, swelling, breathing difficulties, and a sudden drop in blood pressure, potentially leading to shock. Prompt recognition and treatment are crucial.
Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues. Having anemia can make you feel tired and weak. There are many forms of anemia, each with its own cause. Anemia can be temporary or long term, and it can range from mild to severe.
An aneurysm is a bulge or ballooning in a blood vessel caused by a weakness in the vessel wall. This bulge can occur in any blood vessel, but aneurysms are most common in the aorta (the main artery that carries blood from the heart), the brain, and the peripheral arteries (in the legs). If an aneurysm ruptures, it can lead to serious complications, including severe bleeding, stroke, or even death.
Angioedema is characterized by swelling in the deeper layers of the skin, often affecting the face, lips, tongue, throat, genitals, hands, and feet. It can be life-threatening if it affects the airway. Angioedema can be allergic, hereditary, or idiopathic (unknown cause).
Angina is chest pain or discomfort caused when your heart muscle doesn't get enough oxygen-rich blood. It's typically a symptom of underlying heart disease, usually coronary artery disease (CAD), where the arteries that supply blood to the heart become narrowed or blocked. Angina is not a disease in itself but rather a symptom of a problem with the heart.
An angioma is a benign (non-cancerous) tumor composed primarily of blood vessels (hemangioma) or lymphatic vessels (lymphangioma). They can occur anywhere on the body, but are commonly found on the skin, in the brain, or in internal organs. Angiomas vary greatly in size and appearance, and most do not cause any symptoms. Treatment is usually only necessary if they cause cosmetic concerns or functional problems.
Angiomyolipoma (AML) is a benign (non-cancerous) tumor composed of blood vessels (angio-), smooth muscle (myo-), and fat (lipoma). It most commonly occurs in the kidneys, but can also develop in other organs, such as the liver, spleen, and, rarely, elsewhere. Many AMLs are small and asymptomatic, discovered incidentally during imaging for other reasons. Larger AMLs can cause symptoms and may require treatment to prevent complications. AMLs are often associated with genetic conditions like Tuberous Sclerosis Complex (TSC) and Birt-Hogg-Dubé syndrome (BHD), but can also occur sporadically.
Angiopathy refers to a general condition of disease affecting blood vessels (angi/o = vessel, -pathy = disease). It's not a single specific disease, but rather a term describing damage or dysfunction of blood vessels, large or small, throughout the body. This can lead to reduced blood flow, leakage, or abnormal vessel growth. The specific consequences and severity depend on the location and extent of the affected vessels.
Anhidrosis is the inability to sweat normally. Because sweating is essential for regulating body temperature, anhidrosis can lead to overheating, which can be dangerous, especially during physical activity or in hot weather. It can affect a small area, a large area, or the entire body. It's sometimes a symptom of an underlying condition.
Headache
Eye pain
Blurred vision
Double vision
Drooping eyelid (ptosis)
Fever
Neck stiffness
Sensitivity to light (photophobia)
Difficulty moving the eye
An ankle sprain is an injury that occurs when the ligaments that support the ankle are stretched or torn. Ligaments are strong, fibrous tissues that connect bones to each other and help to stabilize joints. Ankle sprains are a common injury, especially among athletes and people who participate in activities that involve running, jumping, or sudden changes in direction.
Ankyloglossia, commonly known as tongue-tie, is a condition present at birth that restricts the tongue's range of motion. It occurs when a short, tight band of tissue (lingual frenulum) connects the bottom of the tongue to the floor of the mouth, limiting tongue movement. In some cases it can cause difficulty breast feeding in infants.
Ankylosing Spondylitis (AS) is a chronic inflammatory disease that primarily affects the spine. It causes inflammation of the spinal joints (vertebrae) that can lead to severe, chronic pain and discomfort. In more advanced stages, this inflammation can lead to ankylosis (new bone formation) causing the spine to fuse in a fixed, immobile position. Other joints, such as the hips, shoulders, and ribs, can also be affected.
Anosmia is the complete loss of the sense of smell. It can be temporary, caused by a cold or allergies, or permanent, resulting from more serious conditions like head trauma or neurological disorders. Anosmia can significantly impact quality of life, affecting taste, appetite, and the ability to detect dangers like gas leaks or spoiled food.
Anorexia nervosa is a serious and potentially life-threatening eating disorder characterized by self-starvation and excessive weight loss. It's driven by an intense fear of gaining weight or becoming fat, along with a distorted perception of body weight and shape. Individuals with anorexia nervosa often place a high value on controlling their weight and shape, using extreme measures that significantly impact their physical and mental health.
Anthrax is a serious infectious disease caused by Bacillus anthracis, a bacterium that forms spores. It most commonly affects livestock and wild animals, but humans can contract it through direct or indirect contact with infected animals. Anthrax can occur in three main forms: cutaneous (skin), inhalation (lungs), and gastrointestinal (digestive system). It is a rare but potentially deadly disease.
Antiphospholipid syndrome (APS) is an autoimmune disorder where the body's immune system mistakenly produces antibodies that attack phospholipids, which are fats important for blood clotting. These antibodies increase the risk of blood clots forming in arteries and veins, and can lead to complications such as stroke, heart attack, deep vein thrombosis (DVT), pulmonary embolism (PE), and pregnancy complications like recurrent miscarriage, stillbirth, and premature birth. APS can occur alone (primary APS) or in association with other autoimmune diseases, such as lupus (secondary APS).
Disregard for right and wrong
Persistent lying or deceit to exploit others
Impulsivity and failure to plan ahead
Irritability and aggressiveness, often resulting in physical fights or assaults
Reckless disregard for the safety of self or others
Consistent irresponsibility, repeatedly failing to fulfill work or financial obligations
Lack of remorse for their actions
Superficial charm and ability to manipulate others
Violation of the rights of others
Arrogance, a sense of superiority and being extremely opinionated
Recurring problems with the law, including criminal behavior
Anxiety is a common mental health condition characterized by excessive worry, fear, or nervousness. It can manifest in various forms, including generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobias. Anxiety disorders can significantly impact daily life, affecting relationships, work, and overall well-being.
Aortic dissection is a serious condition in which a tear occurs in the inner layer of the aorta, the large blood vessel branching off the heart. Blood surges through this tear, causing the inner and middle layers of the aorta to separate (dissect). If the blood-filled channel ruptures through the outside wall of the aorta, it can be life-threatening.
: Aortic stenosis is a condition where the aortic valve, the valve that controls blood flow from the heart to the aorta (the main artery carrying blood to the body), narrows. This narrowing restricts blood flow, forcing the heart to work harder to pump blood through the smaller opening. Over time, this can lead to heart failure and other serious complications.
Apnea is a breathing disorder characterized by pauses in breathing or shallow breaths during sleep. These pauses can occur repeatedly throughout the night, disrupting sleep and reducing oxygen levels in the blood. The most common type is obstructive sleep apnea (OSA), caused by a blockage of the airway, usually when the soft tissue in the back of the throat collapses during sleep. Central sleep apnea (CSA) is less common and occurs when the brain doesn't send proper signals to the muscles that control breathing. Apnea can lead to a variety of health problems if left untreated.
Difficulty speaking (e.g., using incorrect words, substituting words, speaking in short or incomplete sentences)
Difficulty understanding spoken language (e.g., misunderstanding simple questions, difficulty following conversations)
Difficulty reading (e.g., trouble understanding written text)
Difficulty writing (e.g., trouble forming sentences, spelling errors)
Using invented words (neologisms)
Difficulty finding the right words (anomia)
Speaking fluently but without meaning (fluent aphasia)
Difficulty repeating words or phrases
Appendicitis is an inflammation of the appendix, a small pouch attached to the large intestine. It is a medical emergency and usually requires surgical removal of the appendix (appendectomy). If left untreated, an inflamed appendix can eventually burst, spilling infectious material into the abdominal cavity, causing peritonitis, a serious and potentially fatal condition.
Arachnoiditis is a painful and often progressive inflammation of the arachnoid, one of the membranes that surround and protect the brain and spinal cord. This inflammation can cause the arachnoid to thicken, scar, and stick together, potentially damaging the nerve roots within the spinal cord. This can lead to chronic pain, neurological problems, and other complications.
Arrhythmia refers to any irregularity in the heart's rhythm. This means the heart may beat too fast (tachycardia), too slow (bradycardia), or irregularly. It occurs due to problems with the heart's electrical system, which controls the timing of heartbeats. Arrhythmias can range from harmless to life-threatening, depending on the type and severity.
Coronary arteries (heart): Chest pain (angina), shortness of breath
Brain: Sudden numbness or weakness in your arms or legs, difficulty speaking or understanding speech, temporary loss of vision in one eye, drooping face, headache, dizziness
Arms and legs: Leg pain when walking (claudication), numbness, coldness, color change in the affected limb
Kidneys: High blood pressure, kidney failure
Headache
Fatigue
Fever
Muscle aches and pains
Joint pain
Vision problems (blurred vision, double vision, vision loss)
Scalp tenderness
Jaw pain with chewing (claudication)
Arm or leg pain with exertion (claudication)
Skin rashes or nodules
Weight loss
Numbness or weakness
Argyria is a rare condition caused by prolonged exposure to silver, leading to a permanent bluish-gray discoloration of the skin, eyes, and internal organs. It occurs when silver builds up in the body and is deposited in the skin, where it reacts with light to cause the discoloration. Argyria is primarily a cosmetic condition and, in most cases, does not cause significant health problems.
Arthralgia simply means joint pain. It's a symptom, not a disease itself. It can range from mild discomfort to severe, debilitating pain and can affect a single joint or multiple joints throughout the body. Arthralgia can be caused by a wide variety of underlying conditions.
Arthritis is not a single disease; it's an umbrella term for over 100 different conditions that affect the joints, the tissues around the joint, and other connective tissues. It commonly involves joint pain, stiffness, and swelling. The severity and type of arthritis vary widely, ranging from mild discomfort to debilitating pain and disability. Common types include osteoarthritis (OA), rheumatoid arthritis (RA), psoriatic arthritis, and gout.
Stiff, rigid joints
Muscle weakness
Dislocated joints (hips are common)
Cylindrical limbs
Lack of skin creases over joints
Varying degrees of muscle development (some muscles may be missing)
Potential involvement of other organ systems, depending on the underlying cause
Clubfoot
Shortness of breath, especially after exertion
Persistent dry cough
Chest tightness or pain
Loss of appetite
Weight loss
Fatigue
Clubbing of fingers and toes (in advanced stages)
Ascariasis is a parasitic infection caused by the roundworm
Ascaris lumbricoides
. It is the most common soil-transmitted helminth infection worldwide. Infection occurs when people ingest food or water contaminated with
Ascaris
eggs, which hatch in the small intestine and mature into adult worms. These worms can then migrate to other parts of the body, causing a range of symptoms. Often, infections are mild or asymptomatic, but heavy worm burdens can lead to serious complications, particularly in children.
Ascites is the abnormal buildup of fluid in the abdomen. It can be a sign of many underlying conditions, most commonly liver disease, such as cirrhosis. It can also be caused by heart failure, kidney disease, infection, or cancer. Ascites can cause abdominal discomfort, shortness of breath, and other complications.
Aspergillosis is a fungal infection caused by
Aspergillus
, a common mold that lives both indoors and outdoors. Most people breathe in
Aspergillus
spores every day without getting sick. However, in people with weakened immune systems or lung diseases,
Aspergillus
can cause a variety of health problems, ranging from allergic reactions to serious invasive infections. Types of aspergillosis include allergic bronchopulmonary aspergillosis (ABPA), aspergilloma (fungus ball), and invasive aspergillosis.
Gasping for air or difficulty breathing
Rapid breathing or wheezing
Bluish skin color (cyanosis), particularly around the lips and fingertips
Loss of consciousness
Confusion or disorientation
Seizures
Increased heart rate initially, followed by a slowed heart rate
Chest pain or tightness
Agitation
Eventually, respiratory arrest and cardiac arrest.
: Aspiration pneumonia is a lung infection that develops after inhaling food, saliva, liquids, or vomit into the lungs. These substances can carry bacteria that infect the lungs or directly irritate the lung tissue, causing inflammation and infection. It's a serious condition, especially in people with difficulty swallowing, altered consciousness, or impaired cough reflexes.
Asthma is a chronic respiratory disease that causes inflammation and narrowing of the airways, leading to difficulty breathing. It's characterized by recurring episodes of wheezing, chest tightness, shortness of breath, and coughing. Asthma can range from mild and infrequent to severe and persistent, significantly impacting a person's quality of life.
Astigmatism is a common refractive error that causes blurred vision at any distance. It occurs when the cornea (the clear front surface of the eye) or the lens inside the eye isn't perfectly curved. This irregular curvature prevents light from focusing properly on the retina, the light-sensitive tissue at the back of the eye. It is not a disease but a common vision condition.
Ataxia is a degenerative disease affecting the nervous system. It is characterized by a lack of coordination and impaired balance. Ataxia isn't a specific disease itself, but rather a symptom of various underlying conditions that damage the cerebellum (the part of the brain that controls coordination) or the nerve pathways connecting the cerebellum to other parts of the brain and spinal cord. This results in difficulties with movement, speech, and eye control.
Itching, stinging, and burning between the toes or on the soles of the feet.
Cracking, peeling, or scaling skin, especially between the toes and on the heels.
Dry, scaly skin on the soles or sides of the feet.
Inflammation.
Blisters or small fluid-filled vesicles.
Discolored, thick, or crumbly toenails (if the infection spreads to the nails – onychomycosis).
Raw skin on the feet.
Atherosclerosis is a disease in which plaque builds up inside your arteries. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body. Atherosclerosis can lead to serious problems, including heart attack, stroke, or even death.
Atonic seizures, also known as drop attacks, are a type of seizure characterized by a sudden loss of muscle tone, leading to brief collapse or falling. Consciousness may be briefly impaired, or remain intact. The seizures are usually very short, lasting only seconds.
Atopic dermatitis (AD), also known as eczema, is a chronic inflammatory skin condition characterized by intensely itchy, dry, and inflamed skin. It's a common condition, especially in children, but can occur at any age. AD is often associated with other allergic conditions like asthma and hay fever, and it tends to flare up periodically. While there is no cure, various treatments can help manage symptoms and prevent flares.
Atrial fibrillation (AFib) is an irregular and often rapid heart rate that can increase your risk of strokes, heart failure, and other heart-related complications. It occurs when the upper chambers of the heart (atria) beat chaotically and irregularly, out of sync with the lower chambers (ventricles). This uncoordinated beating results in inefficient blood flow to the body.
Atrial flutter is a type of abnormal heart rhythm (arrhythmia) caused by a problem in the heart's electrical system. It occurs when the upper chambers of the heart (atria) beat too quickly and regularly, leading to a faster-than-normal heart rate. The rapid, regular atrial activity causes the ventricles (lower heart chambers) to beat irregularly and often too fast. This can reduce the heart's efficiency, leading to various symptoms and potential complications.
Atrioventricular (AV) block is a type of heart block in which the electrical signal from the atria (upper chambers of the heart) to the ventricles (lower chambers of the heart) is either delayed or completely blocked. This disruption can cause the heart to beat too slowly, leading to various symptoms and potential complications. AV block is classified into three degrees of severity: first-degree (mildest), second-degree (partial block, Mobitz type I and Mobitz type II), and third-degree (complete block).
Atrophy, in the context of medicine, refers to the wasting away or decrease in size of a body tissue, organ, or cell. It results from cell loss or shrinkage due to a variety of factors, leading to a reduction in the affected structure's overall mass. Atrophy can be localized (affecting a specific area) or generalized (affecting the entire body). It's a sign that cells are not being adequately nourished or stimulated.
Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by persistent patterns of inattention, hyperactivity, and impulsivity that interfere with functioning or development. These symptoms are often observed before the age of 12 and can continue into adulthood. ADHD is a common condition, affecting children and adults worldwide. While there is no cure, effective treatments can help manage symptoms and improve quality of life.
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects how a person behaves, interacts with others, communicates, and learns. It is a "spectrum" disorder because there is a wide range of variation in the type and severity of symptoms people experience. It is typically diagnosed in early childhood and is a lifelong condition.
Autoimmune hepatitis is a chronic disease in which the body's immune system attacks the liver, causing inflammation and liver damage. If untreated, it can lead to cirrhosis, liver failure, and even liver cancer. While the exact cause isn't fully understood, genetics and environmental triggers are believed to play a role. Early diagnosis and treatment are crucial to manage the disease and prevent serious complications.
Common symptoms include:
Enlarged lymph nodes (lymphadenopathy)
Enlarged spleen (splenomegaly)
Enlarged liver (hepatomegaly)
Autoimmune cytopenias (destruction of blood cells), such as:
Autoimmune hemolytic anemia (destruction of red blood cells)
Immune thrombocytopenic purpura (ITP, destruction of platelets)
Autoimmune neutropenia (destruction of neutrophils)
Increased risk of developing lymphoma (a type of cancer of the lymphatic system)
Autonomic Dysreflexia (AD) is a syndrome in which there is a sudden onset of excessively high blood pressure. It is more common in people with spinal cord injuries at or above the sixth thoracic vertebra (T6) level, although it can occur with injuries below T6. AD is triggered by noxious (painful or irritating) stimuli below the level of the injury. Because the spinal cord injury blocks communication between the brain and the body, the autonomic nervous system reacts uncontrollably, leading to a dangerous rise in blood pressure. This can lead to serious complications if left untreated.
Axillary hyperhidrosis is a medical condition characterized by excessive sweating in the underarm (axillary) area. This sweating is beyond what is needed to regulate body temperature and can be embarrassing and disruptive to daily life. It's not usually related to an underlying medical condition but is often a chronic problem.
Avascular necrosis (AVN), also known as osteonecrosis, bone infarction, or aseptic necrosis, is a condition that occurs when blood supply to a bone is disrupted, leading to bone cell death. This can eventually cause the bone to collapse. While AVN can affect any bone, it most commonly affects the hip, shoulder, knee, and ankle.
Achondroplasia is a genetic bone growth disorder that causes disproportionate dwarfism. It's characterized by shortened limbs, a relatively large head, and specific facial features. It's the most common form of dwarfism.
Acute Intermittent Porphyria (AIP) is a rare genetic disorder affecting the body's production of heme, a component of hemoglobin. It primarily affects the nervous system and can cause acute attacks of abdominal pain, neurological problems, and psychiatric disturbances. AIP is caused by a deficiency in the enzyme hydroxymethylbilane synthase (also known as porphobilinogen deaminase).
Acquired Hemophilia A (AHA) is a rare autoimmune bleeding disorder where the body's immune system mistakenly produces antibodies (inhibitors) that attack and neutralize clotting factor VIII (FVIII). This leads to impaired blood clotting and an increased risk of bleeding, despite not having a genetic predisposition to hemophilia. Unlike congenital hemophilia, which is present from birth, AHA develops later in life.
Adenocarcinoma is a type of cancer that originates in glandular (secretory) cells of the body. These cells line the internal organs and produce fluids like mucus, digestive juices, and other secretions. Adenocarcinomas can develop in many parts of the body, including the lungs, breast, prostate, pancreas, colon, and esophagus. It's classified as a type of carcinoma, which is a broad category of cancer that begins in the skin or tissues lining organs.
Acute Promyelocytic Leukemia (APL) is a subtype of acute myeloid leukemia (AML), a cancer of the blood and bone marrow. APL is characterized by an abnormal accumulation of immature white blood cells called promyelocytes in the bone marrow. It is a relatively rare form of AML but is highly treatable, particularly with modern therapies. APL is distinguished from other types of AML by a specific chromosomal translocation (t(15;17)) involving the retinoic acid receptor alpha (RARα) gene. This translocation disrupts normal blood cell development.
Adenosquamous carcinoma is a rare and aggressive type of cancer that contains features of both adenocarcinoma (gland-forming cancer) and squamous cell carcinoma (cancer arising from skin-like cells). It can occur in various organs, including the lungs, pancreas, esophagus, and uterus. Due to its mixed nature, adenosquamous carcinoma often presents with a poorer prognosis than either adenocarcinoma or squamous cell carcinoma alone.
Adie syndrome, also known as tonic pupil or Holmes-Adie syndrome, is a rare neurological disorder characterized by a slowly reacting pupil (tonic pupil) in one eye, often accompanied by absent or diminished deep tendon reflexes, usually in the legs. The condition is generally benign and often affects young women.
Adiposis Dolorosa (also known as Dercum's disease) is a rare disorder characterized by multiple, painful lipomas (fatty tumors) under the skin. It typically affects women more than men and often begins in middle age. The pain associated with these lipomas is often disproportionate to their size and can be constant, burning, or aching. The condition can also be associated with fatigue, weakness, cognitive difficulties, and other systemic symptoms.
Symptoms vary depending on the type and severity of ALD.
Childhood Cerebral ALD (CCALD): Behavioral problems (aggression, withdrawal), vision problems, learning difficulties, difficulty understanding speech, coordination problems, muscle weakness, seizures, and progressive loss of cognitive function.
Adrenomyeloneuropathy (AMN): This adult-onset form primarily affects the spinal cord. Symptoms include stiffness and weakness in the legs, bladder and bowel dysfunction, sexual dysfunction, and sensory loss. Cognitive problems can also develop later.
Adrenal Insufficiency (Addison's Disease): Weakness, fatigue, weight loss, skin darkening, nausea, vomiting, and low blood pressure. This can occur in all forms of ALD.
Adult T-cell Leukemia/Lymphoma (ATL) is a rare and aggressive cancer of T-cells caused by the human T-cell lymphotropic virus type 1 (HTLV-1). It can manifest in different forms, ranging from chronic and smoldering to acute and lymphoma types. The acute form is the most aggressive, progressing rapidly. ATL is characterized by abnormal proliferation of infected T-cells.
Afibrinogenemia is an extremely rare, inherited bleeding disorder characterized by the complete absence of fibrinogen in the blood. Fibrinogen is a protein essential for blood clot formation. Without it, the blood cannot clot properly, leading to prolonged and sometimes life-threatening bleeding. It is usually diagnosed in infancy or early childhood.
Aglossia-Adactylia Syndrome is a very rare congenital disorder characterized by the absence or malformation of the tongue (aglossia) and the absence or malformation of digits (adactylia) on the hands and/or feet. The severity of the condition varies considerably from case to case. Other abnormalities, such as cleft palate, limb defects, and craniofacial anomalies, may also be present. It's extremely rare and not fully understood.
Agyria, also known as Lissencephaly ("smooth brain"), is a rare brain malformation characterized by the absence of normal folds (gyri) in the cerebral cortex. This results in a smaller, smoother brain surface, impacting cognitive and motor functions. It is a severe developmental condition with significant neurological consequences.
Alagille syndrome (ALGS) is a genetic disorder that primarily affects the liver, heart, and other body systems. It is characterized by a reduced number of small bile ducts in the liver, which leads to bile buildup and liver damage. ALGS can also cause heart defects, eye abnormalities, skeletal problems, and distinctive facial features. The severity of ALGS varies greatly, with some individuals experiencing mild symptoms and others developing life-threatening complications.
Albright Hereditary Osteodystrophy (AHO) is a rare genetic disorder primarily characterized by resistance to parathyroid hormone (PTH). This resistance leads to hypocalcemia (low blood calcium), hyperphosphatemia (high blood phosphorus), and elevated PTH levels. AHO also presents with distinctive physical features including short stature, round face, brachydactyly (shortening of fingers and toes), and subcutaneous ossifications (bone formation under the skin).
Alcohol Withdrawal Syndrome (AWS) is a set of symptoms that can occur when someone who has been drinking heavily stops or significantly reduces their alcohol intake. The severity of AWS can range from mild anxiety and tremor to severe complications like seizures and delirium tremens (DTs), which can be life-threatening. The development and severity of AWS depend on factors like the duration and amount of alcohol consumed, as well as individual health factors.
Alder-Reilly anomaly is a rare, inherited genetic condition characterized by the presence of large, abnormally staining granules in the cytoplasm of white blood cells (leukocytes), particularly neutrophils. It is often associated with mucopolysaccharidoses (MPS), a group of metabolic disorders. However, it can also occur as a benign, isolated finding. It does not usually cause any symptoms itself, but its presence can indicate an underlying MPS disorder.
Alexia is an acquired reading disorder caused by brain damage. It is characterized by the inability to read, despite preserved language comprehension, speech, and often writing skills. It is not a developmental learning disability like dyslexia, but rather a loss of a previously acquired ability. There are different types of alexia, each with its own characteristics and underlying neurological basis.
Alkaptonuric ochronosis is a rare inherited metabolic disorder characterized by the body's inability to properly break down two amino acids: tyrosine and phenylalanine. This leads to the accumulation of homogentisic acid (HGA) in the body, which is deposited in various tissues, particularly cartilage, causing it to darken and become brittle. This accumulation leads to a range of symptoms, including dark urine, arthritis, and heart valve problems.
Allergic Bronchopulmonary Aspergillosis (ABPA) is an allergic reaction to a fungus called Aspergillus, most commonly
Aspergillus fumigatus
. This fungus is common in the environment, and most people breathe in its spores without any problems. However, in individuals with asthma or cystic fibrosis, the spores can trigger an allergic response in the lungs, leading to inflammation and lung damage. It is not an infection but rather an allergic response.
1. Summary about disease: Allergic conjunctivitis is inflammation of the conjunctiva (the membrane lining the eyelid and covering the white part of the eye) caused by an allergic reaction. It is not contagious and typically affects both eyes. The allergic reaction occurs when the eye comes into contact with an allergen.
Allergic contact dermatitis (ACD) is an inflammatory skin condition that occurs when the skin comes into contact with a substance that triggers an allergic reaction. This reaction leads to redness, itching, blisters, and other uncomfortable skin changes at the point of contact. It is a type IV hypersensitivity reaction, a delayed immune response, meaning symptoms develop 12-72 hours after exposure.
Allergic rhinitis, commonly known as hay fever, is an inflammation of the nasal passages caused by an allergic reaction to airborne allergens like pollen, dust mites, mold, or animal dander. It's a common condition that can significantly impact quality of life, leading to symptoms like sneezing, runny nose, congestion, and itchy eyes. It's not an infection and is not contagious.
The primary symptom of Alopecia Totalis is the complete loss of all hair on the scalp. This hair loss typically occurs rapidly and without any visible signs of inflammation, such as redness or scaling, on the scalp itself. Some individuals might experience itching, burning, or tingling sensations on the scalp before the hair loss begins, but these symptoms are not universal. Hair loss can sometimes be preceded by alopecia areata (patchy hair loss).
Alopecia Universalis is a rare autoimmune disease characterized by the complete loss of all hair on the body, including the scalp, eyebrows, eyelashes, and body hair. It is a more severe form of alopecia areata, which typically involves patchy hair loss. The condition develops when the immune system mistakenly attacks hair follicles, leading to hair loss. There is currently no cure for alopecia universalis, but various treatments can help manage the condition and potentially stimulate hair regrowth.
Alpha thalassemia is a genetic blood disorder that reduces the production of hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. Reduced hemoglobin leads to a shortage of red blood cells (anemia), which can cause fatigue, weakness, paleness, and other health problems. The severity of alpha thalassemia depends on how many genes are affected. There are four alpha globin genes, and individuals can inherit zero to four defective genes. The more defective genes, the more severe the anemia. Alpha thalassemia is most common in people of Southeast Asian, Chinese, Mediterranean, and African descent.
Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by the abnormal accumulation of surfactant-derived lipoprotein in the alveoli (air sacs) of the lungs. This buildup impairs gas exchange, leading to breathing difficulties. PAP can be congenital (present at birth), secondary to other conditions, or autoimmune (most common). The autoimmune form is caused by antibodies that neutralize granulocyte-macrophage colony-stimulating factor (GM-CSF), a protein essential for surfactant clearance by alveolar macrophages.
Amelogenesis imperfecta (AI) is a group of inherited disorders that affect the enamel formation of teeth. It results in teeth that are abnormally thin, soft, discolored, and easily damaged. The condition affects both primary (baby) and permanent teeth. The severity of AI can vary greatly from person to person.
Ameloblastoma is a rare, benign (non-cancerous) odontogenic tumor, meaning it originates from the cells that form teeth. It typically occurs in the jaw, most often in the mandible (lower jaw) near the molars. Although benign, ameloblastomas are locally aggressive, meaning they can invade and destroy surrounding bone tissue. They tend to grow slowly and may be asymptomatic for some time before being discovered. Recurrence after treatment is possible.
Amniotic Band Syndrome (ABS) is a rare condition that occurs when fibrous strands of the amniotic sac (the sac surrounding the developing fetus in the womb) become detached and entangle or constrict parts of the fetus, most commonly the limbs, fingers, or toes. This can lead to a variety of birth defects, ranging from mild constrictions to severe amputations.
Amphetamine dependence is a chronic, relapsing disorder characterized by compulsive amphetamine seeking and use despite negative consequences. It develops from repeated exposure to amphetamines, leading to changes in brain structure and function that reinforce drug-seeking behavior. This dependence can significantly impair an individual's physical and mental health, social relationships, and overall well-being.
An amputation neuroma is a painful condition that occurs when nerve fibers at the site of an amputation attempt to regenerate but become entangled, forming a mass of nerve tissue. This mass can become hypersensitive and cause significant pain. It's essentially a disorganized growth of nerve endings after a limb or other body part has been surgically removed.
Amyloid polyneuropathy, specifically Familial Amyloid Polyneuropathy (FAP), also known as hereditary transthyretin-related amyloidosis (ATTR amyloidosis), is a rare, progressive genetic disorder characterized by the buildup of abnormal amyloid protein, particularly transthyretin (TTR), in the peripheral nerves, heart, and other organs. This deposition disrupts the normal function of these tissues, leading to a variety of symptoms, most prominently affecting the nerves and resulting in neuropathy. The condition is inherited, meaning it is passed down through families via mutated genes. The severity and age of onset vary greatly between individuals, even within the same family.
Amyotrophic Lateral Sclerosis Type 2 (ALS2), also known as Juvenile ALS or ALS2, is a rare, early-onset form of amyotrophic lateral sclerosis. It is characterized by progressive muscle weakness and wasting, typically beginning in childhood or adolescence. It differs from the more common, late-onset ALS (ALS1) in terms of genetic cause and typical age of onset.
Anal cancer is a relatively rare cancer that forms in the tissues of the anus, the opening at the end of the rectum through which stool passes from the body. Most anal cancers are squamous cell carcinomas, arising from the cells that line the anal canal. It's often associated with human papillomavirus (HPV) infection. Early detection is crucial for successful treatment.
Anaplastic astrocytoma is a type of brain tumor that arises from star-shaped glial cells called astrocytes. It is classified as a grade III tumor by the World Health Organization (WHO), indicating that it is malignant (cancerous) and grows relatively quickly. Anaplastic astrocytomas are more aggressive than low-grade astrocytomas but less aggressive than glioblastomas (grade IV).
Anaplastic Large Cell Lymphoma (ALCL) is a type of non-Hodgkin lymphoma. It is a cancer of the lymphatic system, which is part of the immune system. ALCL primarily affects T-cells, a type of white blood cell. There are different subtypes of ALCL, including systemic ALCL (ALK-positive and ALK-negative) and primary cutaneous ALCL (skin-only ALCL). ALCL can occur in both children and adults.
Anemia of Chronic Disease (ACD), also known as anemia of inflammation, is a type of anemia that occurs in people with long-term (chronic) medical conditions. It's characterized by a reduced number of red blood cells due to chronic inflammation disrupting the body's ability to use iron normally. It is the second most common type of anemia worldwide.
An aneurysmal bone cyst (ABC) is a benign, but locally aggressive, bone tumor characterized by blood-filled cystic spaces. While not cancerous, ABCs can expand and damage surrounding bone tissue, potentially leading to pain, swelling, and fractures. They typically occur in long bones (like the femur or tibia) and the spine, often affecting children and young adults. There are two types: primary (arising spontaneously) and secondary (developing within a pre-existing bone lesion like a giant cell tumor).
Angelman Syndrome (AS) is a complex genetic disorder that primarily affects the nervous system. It's characterized by intellectual disability, developmental delay, speech impairment, movement or balance disorders (ataxia), a happy demeanor with frequent smiling and laughter, and sometimes seizures. Individuals with AS often have a characteristic facial appearance. It is rare and is not a degenerative condition; that is, symptoms do not worsen with age.
Angina pectoris is chest pain or discomfort caused by reduced blood flow to the heart muscle. It's usually a symptom of coronary artery disease (CAD). Angina is not a disease in itself but a symptom of an underlying heart problem. It often feels like squeezing, pressure, heaviness, or tightness in the chest. Angina can be stable (predictable and triggered by exertion) or unstable (unexpected and may occur at rest).
Angiokeratomas are benign skin lesions characterized by small, dark red to bluish-black papules. They are caused by dilated blood vessels (angiomas) close to the skin's surface covered by a thickened epidermis (keratosis). While generally harmless, they can sometimes be mistaken for more serious conditions. Different types exist, including solitary, multiple (angiokeratoma corporis diffusum), and those associated with underlying medical conditions like Fabry disease.
Angiolipomas are benign (non-cancerous) subcutaneous tumors composed of mature fat cells (lipocytes) and an abnormal proliferation of blood vessels (angioma). They are typically small, soft, and mobile nodules that occur most often in the subcutaneous tissue of the trunk and extremities. They are often painful, unlike typical lipomas.
Angiosarcoma is a rare and aggressive type of cancer that develops in the lining of blood vessels and lymph vessels. It can occur anywhere in the body, but it's most often found in the skin, breast, liver, spleen, and deep tissue. Angiosarcomas are often fast-growing and can be difficult to treat.
Aniridia is a rare genetic disorder characterized by the complete or partial absence of the iris (the colored part of the eye). The term "aniridia" literally means "absence of iris," but in most cases, a small amount of iris tissue remains. Aniridia is not just an absence of the iris; it often involves other eye structures and can lead to a range of visual problems. The severity can vary greatly from person to person. Aniridia often occurs with other ocular conditions.
Anarthria is a severe motor speech disorder characterized by the inability to articulate words. It is the most extreme form of dysarthria. Individuals with anarthria have difficulty or are completely unable to produce speech sounds due to impaired control of the muscles used for speech, including those of the lips, tongue, jaw, and vocal cords. It's crucial to remember that anarthria is a speech disorder and
not
a language disorder. People with anarthria may still understand language and have the ability to communicate through writing, gestures, or assistive technology, even though they cannot speak clearly.
An ankle fracture is a break in one or more of the bones that make up the ankle joint. These bones include the tibia (shinbone), fibula (smaller bone in the lower leg), and talus (a bone in the foot that fits into the tibia and fibula to form the ankle joint). Fractures can range from hairline cracks to complete breaks where the bone pierces the skin (open fracture). The severity of an ankle fracture depends on the number of bones broken, the stability of the fracture, and any associated ligament damage.
Early Detection is Key: Early detection and treatment of anisometropia in children are crucial to prevent amblyopia and ensure proper visual development.
Compliance with Treatment: Consistent wear of glasses or contact lenses is essential for effective correction and to prevent the worsening of amblyopia.
Regular Eye Exams: Regular comprehensive eye exams are recommended for all ages to monitor for anisometropia and other eye conditions.
Tolerance to Correction: Large differences in refractive power between the eyes can sometimes be difficult to tolerate initially with eyeglasses. The brain may need time to adjust. Contact lenses can often provide a more comfortable and natural visual experience in these cases.
Amblyopia Therapy: If amblyopia is present, dedicated treatment (patching or blurring drops) is critical to improve vision in the weaker eye. The earlier treatment is started, the better the outcome.
Annular pancreas is a rare congenital anomaly where the pancreas forms a ring around the duodenum (the first part of the small intestine). This ring can constrict the duodenum, causing obstruction. The severity of the obstruction can vary, leading to a range of symptoms from mild discomfort to complete blockage. It is typically diagnosed in infancy or early childhood, but milder cases can go unnoticed until adulthood.
Anomalous Pulmonary Venous Return (APVR), also known as Total Anomalous Pulmonary Venous Connection (TAPVC) or Partial Anomalous Pulmonary Venous Connection (PAPVC), is a congenital heart defect. In this condition, the pulmonary veins, which normally carry oxygen-rich blood from the lungs to the left atrium of the heart, connect abnormally to other blood vessels or the right atrium. This causes oxygen-rich blood to mix with oxygen-poor blood, reducing the amount of oxygen delivered to the body. The severity of the condition depends on the degree of mixing and the presence of other heart defects.
Anophthalmia is a rare birth defect where one or both eyes fail to develop completely during pregnancy. It can range from the complete absence of one or both eyeballs to the presence of very small, underdeveloped eyes. It's considered a severe congenital condition with significant visual implications.
An Anterior Cruciate Ligament (ACL) tear is an injury to one of the major ligaments in your knee. ACLs are strong bands of tissue that help connect your thigh bone (femur) to your shinbone (tibia). ACL tears most commonly occur during sports that involve sudden stops or changes in direction, jumping, and landing, such as soccer, basketball, football, and skiing. Treatment options range from conservative management (bracing, physical therapy) to surgical reconstruction, depending on the severity of the tear and the individual's activity level.
Anterior uveitis is inflammation of the uvea, specifically the front part of the eye (iris and ciliary body). It can occur suddenly and severely (acute), or develop gradually (chronic). It's a relatively common eye condition that can affect people of all ages, although it's more frequently seen in young and middle-aged adults. If left untreated, it can lead to serious complications, including vision loss.
An aortic aneurysm is an abnormal bulge or swelling in the aorta, the body's main artery that carries blood from the heart to the rest of the body. Aneurysms can occur anywhere along the aorta but are most common in the abdomen (abdominal aortic aneurysm) or chest (thoracic aortic aneurysm). The primary danger is rupture, which can lead to life-threatening internal bleeding. Smaller, slow-growing aneurysms might not pose an immediate threat.
Aortic coarctation is a congenital heart defect characterized by a narrowing of the aorta, the main artery that carries blood from the heart to the rest of the body. This narrowing restricts blood flow, forcing the heart to work harder to pump blood through the aorta. The severity of coarctation can vary, ranging from mild to severe.
Aortic regurgitation (AR), also known as aortic insufficiency, is a condition that occurs when the aortic valve doesn't close properly, causing blood to flow backward from the aorta into the left ventricle of the heart. This backward flow forces the left ventricle to work harder to pump blood, which can eventually lead to heart failure if left untreated. AR can develop gradually or suddenly.
Sudden, severe chest or back pain (described as tearing or ripping)
Loss of consciousness
Shortness of breath
Rapid heart rate
Low blood pressure
Sweating
Anxiety and agitation
Weakness or paralysis (if the spinal cord is affected)
Difference in blood pressure between arms
Pulse deficits (absence of pulse in certain areas)
Aortitis is inflammation of the aorta, the body's largest artery. This inflammation can weaken the aortic wall, leading to aneurysms (bulges) or narrowing (stenosis), which can disrupt blood flow and potentially cause life-threatening complications such as aortic dissection or rupture. It can be caused by various factors, including autoimmune diseases, infections, and other inflammatory conditions.
Apert syndrome is a rare genetic disorder characterized by malformations of the skull, face, hands, and feet. The most distinctive feature is craniosynostosis, where certain skull bones fuse prematurely, affecting the shape of the head and face. Syndactyly, or fusion of the fingers and toes, is also a common characteristic. The severity of symptoms can vary widely among individuals with Apert syndrome.
Aplastic anemia is a rare and serious blood disorder where the bone marrow fails to produce enough new blood cells. This results in a deficiency of all three types of blood cells: red blood cells (causing anemia), white blood cells (increasing risk of infection), and platelets (leading to bleeding problems). Aplastic anemia can be acquired or inherited. It can develop slowly over time or suddenly.
Apraxia is a neurological disorder characterized by the inability to perform learned (familiar) movements on command, even though the person understands the command and has the willingness and physical capacity to perform the movement. It is not due to muscle weakness, paralysis, sensory loss, or lack of comprehension. It results from damage to areas of the brain involved in motor planning and execution. Different types of apraxia exist, affecting different motor skills like speech (verbal apraxia), limb movement, or eye movement.
Arcus senilis is a common age-related condition characterized by a gray or white arc or circle visible in the outer part of the cornea of the eye. It is caused by the deposition of lipid (fat) in the peripheral corneal stroma. While often associated with aging, it can occur at a younger age, in which case it may be linked to hyperlipidemia (high cholesterol). Arcus senilis typically does not affect vision.
Arnold-Chiari malformation (ACM) is a structural defect in the base of the skull and cerebellum. Specifically, it involves the cerebellum, the part of the brain that controls balance, protruding down through the foramen magnum (the opening at the base of the skull) and into the spinal canal. This can put pressure on the brain and spinal cord, leading to a variety of neurological symptoms. The severity and presentation of ACM can vary greatly between individuals. There are several types of ACM, classified by the degree and type of brain tissue that is displaced into the spinal canal.
An arteriovenous malformation (AVM) is an abnormal tangle of blood vessels connecting arteries and veins, disrupting normal blood flow and oxygen circulation. Arteries carry oxygen-rich blood from the heart to the brain and other organs. Veins carry oxygen-depleted blood back to the heart and lungs. When an AVM disrupts this critical process, tissues may not get enough oxygen. AVMs can occur in the brain, spine, or other parts of the body. Brain AVMs are of greatest concern due to potential neurological damage.
Arsenic poisoning occurs when arsenic, a naturally occurring element found in soil, water, and air, enters the body in harmful amounts. It can happen acutely (large dose at once) or chronically (small doses over a long period). Arsenic is toxic because it interferes with cellular enzymes and processes, leading to organ damage and potentially death.
Arthralgia: Arthralgia refers to joint pain. It is a symptom, not a disease itself. It can be caused by a wide range of conditions, from minor injuries to serious underlying diseases.
Meralgia Paresthetica: Meralgia paresthetica is a nerve condition characterized by tingling, numbness, and burning pain in the outer thigh. It is caused by compression of the lateral femoral cutaneous nerve, which supplies sensation to the skin surface of the thigh.
Arthroscopic surgery complications encompass a range of adverse events that can occur during or after an arthroscopic procedure. Arthroscopy is a minimally invasive surgical technique used to visualize, diagnose, and treat joint problems. While generally safe, complications can arise due to the surgical procedure itself, pre-existing patient conditions, or post-operative factors. Complications can range from minor issues like wound infection to more serious conditions such as nerve damage or blood clots.
Articular cartilage injury refers to damage to the smooth, white tissue that covers the ends of bones where they meet to form a joint. This cartilage allows for nearly frictionless joint motion. Damage can range from minor surface irregularities to full-thickness defects exposing the underlying bone. This can lead to pain, stiffness, and reduced joint function.
Social Difficulties: Trouble understanding social cues, difficulty making and maintaining friendships, seeming aloof or disinterested in others, difficulty engaging in reciprocal conversations, trouble understanding humor or sarcasm, may appear socially awkward.
Restricted Interests and Repetitive Behaviors: Intense focus on specific topics or interests, repetitive movements (stimming) such as hand-flapping or rocking, adherence to routines or rituals, difficulty with transitions or changes in routine, sensory sensitivities (e.g., to light, sound, or touch).
Communication Differences: Difficulty understanding nonverbal communication (e.g., facial expressions, body language), atypical speech patterns (e.g., monotone voice, formal or pedantic language), difficulty understanding abstract concepts.
Motor Skills: Some individuals may exhibit clumsiness or uncoordinated movements.
Cognitive Strengths: Often possess above-average intelligence and strong skills in specific areas (e.g., mathematics, science, music).
Astrocytomas are a type of tumor that arises from astrocytes, star-shaped glial cells in the brain and spinal cord. They are the most common type of glioma (a tumor arising from glial cells). Astrocytomas can be benign and slow-growing, or malignant and aggressive. The grade of the astrocytoma (I-IV) indicates its aggressiveness, with higher grades indicating faster growth and more aggressive behavior.
Ataxia-telangiectasia (A-T) is a rare, inherited genetic disorder that affects the nervous system, immune system, and other body systems. It is characterized by progressive difficulty with coordination (ataxia), small widened blood vessels (telangiectasias), and an increased risk of infections and cancer. A-T is caused by mutations in the ATM gene, which plays a role in DNA repair and cell cycle control.
Atrial myxoma is a rare, noncancerous (benign) tumor that grows in the heart. It is the most common type of primary cardiac tumor in adults. Most atrial myxomas grow in the left atrium (the upper left chamber of the heart). These tumors can interfere with the heart's function by obstructing blood flow, damaging heart valves, or releasing fragments that travel to other parts of the body, causing various complications.
Aspiration refers to the entry of food, liquid, saliva, or other foreign material into the lungs. This can occur when a person has difficulty swallowing (dysphagia) or when the body's natural defenses against foreign materials entering the airway are compromised. Aspiration can lead to serious complications like pneumonia, lung damage, and even death.
1. Summary about disease: Atrioventricular Septal Defect (AVSD), also known as atrioventricular canal defect (AV canal defect) or endocardial cushion defect, is a congenital heart defect characterized by holes between the heart's chambers (atria and ventricles) and abnormalities of the tricuspid and mitral valves (which may be fused into a single common valve). This allows blood to flow abnormally between all four chambers of the heart. It can be partial (incomplete) or complete, depending on the extent of the defect.
Fatigue and weakness
Frequent infections
Easy bruising or bleeding (e.g., nosebleeds, bleeding gums)
Petechiae (tiny red spots under the skin)
Bone pain
Weight loss
Fever
Shortness of breath
1. Summary about disease Auditory Processing Disorder (APD), also known as Central Auditory Processing Disorder (CAPD), is a condition where the brain has difficulty processing sounds. This means individuals with APD can hear sounds, but struggle to understand them, especially in noisy environments. It is not a hearing loss issue, but rather a deficit in how the brain interprets auditory information.
Aura, in the context of migraines or seizures, refers to a sensory disturbance that precedes the headache or seizure itself. It can manifest in various forms, including visual disturbances (like flashing lights or zig-zag lines), sensory changes (numbness or tingling), motor weakness, or speech difficulties. Not everyone with migraines or epilepsy experiences auras. Auras typically last a short period, ranging from a few minutes to an hour, and then resolve, often followed by the main event (headache or seizure).
Autoimmune Thrombocytopenic Purpura (ITP), also known as Immune Thrombocytopenic Purpura, is an autoimmune disorder where the immune system mistakenly attacks and destroys platelets, which are essential for blood clotting. This leads to a lower-than-normal platelet count (thrombocytopenia), increasing the risk of bleeding and bruising. ITP can be acute (short-term) or chronic (long-term).
Influenza (Flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. It can cause mild to severe illness, and at times can lead to death. The best way to prevent the flu is by getting a flu vaccine each year.
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