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Kidney Infection

A kidney infection, medically known as pyelonephritis, occurs when bacteria, usually E coli, spread from the bladder up the urinary tract to one or both kidneys.

The symptoms of a kidney infection may appear very quickly and often match those of a bladder or urinary tract infection, but a kidney infection is usually more serious. Severe or recurrent infections may cause permanent kidney damage and lead to chronic kidney disease. In rare cases, infection in the kidney may spread to poison the bloodstream in a serious condition called sepsis. Diabetics are at significant risk for pyelonephritis Acute renal failure, a temporary condition in which the kidneys stop working, can also result.

Women are at greater risk of kidney infection than are men. This is because a woman's urethra is shorter than a man's, making it easier for bacteria to reach their kidneys. Young children, particularly those with urinary reflux, are also vulnerable because of their delicate urinary tracts. Pregnant women who experience a kidney infection are at higher risk of complications, including delivering a low-birth-weight baby. People with diabetes, or another disorder that compromises the immune system, have a higher risk of a kidney infection. Sexual activity increases the risk for infections.

Any abnormality of the urinary tract that obstructs the flow of urine (a kidney stone or an enlarged prostate gland, for example) can cause an infection. Repeated kidney infections may indicate a urologic condition or abnormality that requires surgery. Recurring kidney infections should always be evaluated by a urologist or urogynecologic specialist.

Symptoms of a Kidney Infection

  • Back, side, and groin pain
  • Urgent and frequent urination
  • Pain or burning during urination
  • Fever
  • Nausea and vomiting
  • Blood and/or discharge in the urine

Testing for a Kidney Infection

  • Urinalysis
  • Blood tests
  • Physical and pelvic exams
  • Abdominal ultrasound

Treatment for a Kidney Infection

  • Oral antibiotics taken for several weeks
  • Severely ill patients with kidney infections may be hospitalized and receive antibiotics intravenously until they can take fluids and needed drugs on their own.

Prevention of a Kidney Infection

Doctors suggest these preventative measures to avoid a kidney infection:

  • Drink plenty of water (six to eight glasses) every day.
  • Do not resist the urge to urinate. Bacteria can grow when urine stays in the bladder too long.
  • Women should wipe from front to back to prevent bacteria from entering the vagina or urethra.
  • Take showers instead of tub baths.
  • Cleanse the genital area before and after sexual intercourse.
  • Urinate shortly after sex. This can flush away bacteria that might have entered the urethra during sex. Drinking a glass of water will also help.
  • Avoid using feminine hygiene sprays and scented douches, which may irritate the urethra.


Medical Disclaimer: The information provided in the Bladder Health Program of South Florida website should be used solely for educational purposes. It is not intended to replace the independent judgment of a healthcare provider. The appropriateness of a course of treatment for a patient may vary from the medical information provided herein due to individual conditions and/or complications. Always ask your physician about all treatment options, as well as the risks and benefits.

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