Acute Pyelonephritis: Causes, Symptoms, Diagnosis, and Treatment


Acute pyelonephritis is a severe and potentially life-threatening bacterial infection of the kidneys. It typically occurs when bacteria from the urinary tract ascend into the kidneys, leading to inflammation and possible kidney damage. Prompt medical attention and appropriate treatment are essential to prevent complications. In this article, we will explore the causes, symptoms, diagnosis, and treatment options for acute pyelonephritis, shedding light on this serious kidney condition.


Acute pyelonephritis is primarily caused by bacterial infection, with Escherichia coli (E. coli) being the most common culprit. The bacteria usually enter the urinary tract through the urethra and ascend into the bladder. From there, they can reach the kidneys, causing infection and inflammation. If not promptly treated, acute pyelonephritis can lead to permanent kidney damage and other complications.


The symptoms of acute pyelonephritis may include:

  • High fever and chills
  • Flank pain (pain in the sides of the back, below the ribs)
  • Painful or frequent urination
  • Cloudy or bloody urine
  • Nausea and vomiting
  • General fatigue or malaise


The primary cause of acute pyelonephritis is a bacterial infection, often due to:

  • Untreated urinary tract infections (UTIs): Bacteria from an untreated UTI can ascend into the kidneys.
  • Kidney stones or obstruction: Blockages in the urinary tract can create conditions favorable for bacterial growth and infection.
  • Reflux: A condition where urine flows backward from the bladder to the kidneys, increasing the risk of infection.
  • Urinary catheterization: Catheters can introduce bacteria into the urinary tract.


Diagnosing acute pyelonephritis typically involves a combination of medical history, physical examination, and diagnostic tests, which may include:

  • Urinalysis: This test analyzes a urine sample for the presence of bacteria, white blood cells, and other indicators of infection.
  • Urine culture: A culture is performed to identify the specific bacteria causing the infection and determine its susceptibility to antibiotics.
  • Blood tests: Blood tests can help assess kidney function and detect signs of infection.
  • Imaging: Imaging tests like ultrasound or CT scans may be used to visualize the kidneys and urinary tract for signs of obstruction or other abnormalities.


Treatment for acute pyelonephritis typically involves:

  • Antibiotics: Appropriate antibiotics are prescribed based on the results of urine culture and sensitivity testing.
  • Hydration: Drinking plenty of fluids helps flush out bacteria and support kidney function.
  • Pain management: Over-the-counter pain relievers may be recommended to alleviate discomfort.
  • Rest: Getting adequate rest aids in the body's recovery process.


Preventing acute pyelonephritis involves maintaining good urinary tract health, such as:

  • Drinking plenty of water to stay hydrated
  • Urinating frequently and fully emptying the bladder
  • Wiping from front to back after using the bathroom
  • Avoiding the use of harsh or scented soaps in the genital area
  • Managing underlying conditions, such as kidney stones or urinary reflux


Acute pyelonephritis is a serious bacterial infection of the kidneys that requires timely diagnosis and appropriate treatment. If you experience symptoms of acute pyelonephritis, seek medical attention promptly to prevent complications and kidney damage. Practicing good urinary tract hygiene and managing underlying risk factors can help reduce the risk of infection and promote kidney health.

Disclaimer: This article is for informational purposes only and should not replace professional medical advice. Always consult with a qualified healthcare provider for accurate diagnosis and treatment options specific to your condition.