What is kidney infection?

Kidney Infection

Kidney infection (pyelonephritis)

A kidney infection occurs when bacteria travel from the bladder up the ureters and into the kidneys. Sometimes kidney infections may occur when bacteria in the blood enter the kidneys.

Symptoms of kidney infection may include:

  • Painful urination and other symptoms of a bladder infection.
  • Pain in the flank, which is felt just below the rib cage and above the waist on one or both sides of the back.
  • Fever.
  • Nausea and vomiting.

Oral antibiotics usually can treat kidney infections. But a brief hospital stay and a short course of intravenous (I.V.) antibiotics are sometimes required. If not treated with antibiotics, the infection may damage the kidneys. The infection may also spread to the bloodstream and become life-threatening, especially in young children and the elderly.

How can you care for a kidney infection?

  • Take your antibiotics as directed. Do not stop taking them just because you feel better. You need to take the full course of antibiotics.
  • Drink plenty of water. This may help wash out bacteria that are causing the infection. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase the amount of fluids you drink.
  • Urinate often. Try to empty your bladder each time.
  • To relieve pain, take a hot shower or lay a heating pad (set on low) over your lower belly. Never go to sleep with a heating pad in place. Put a thin cloth between the heating pad and your skin.

To help prevent kidney infections

  • Drink plenty of water each day. This helps you urinate often, which clears bacteria from your system. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase the amount of fluids you drink.
  • Urinate when you have the urge. Do not hold your urine for a long time. Urinate before you go to sleep.
  • If you have symptoms of a bladder infection, such as burning when you urinate or having to urinate often, call your doctor so you can treat the problem before it gets worse. If you do not treat a bladder infection quickly, it can spread to the kidney.
  • Men should keep the tip of the penis clean.

If you are a woman, keep these ideas in mind:

  • Urinate right after you have sex.
  • Change sanitary pads often. Avoid douches, feminine hygiene sprays, and other feminine hygiene products that have deodorants.
  • After going to the bathroom, wipe from front to back.

Kidney infection in children: When to call

Call your doctor now or seek immediate medical care if:

  • Your child has symptoms that a kidney infection is getting worse. These may include:
    • Pain or burning when he or she urinates.
    • A frequent need to urinate without being able to pass much urine.
    • Pain in the flank, which is just below the rib cage and above the waist on either side of the back.
    • Blood in the urine.
    • A fever.
  • Your child is vomiting or nauseated.

Watch closely for changes in your child's health, and be sure to contact your doctor if:

  • Your child is vomiting or cannot take his or her antibiotic.
  • Your child does not get better as expected.

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The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.