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Pyelonephritis (Kidney Infection)

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What is pyelonephritis?

Pyelonephritis is a bacterial infection of the kidney. It can be serious because of the important function of the kidneys. Also, the infection may enter the bloodstream. Another problem is that it can cause pregnant women to go into labor too early (premature labor).

Kidney infections are much more common in women than men.

How does it occur?

Most kidney infections result from lower urinary tract infections, usually bladder infections.

Bladder infections can happen when bacteria travel from the vagina or rectal area (anus) into the urethra and bladder. The urethra is the tube that empties urine from the bladder. A woman's urethra is short, about 2 inches long. It is just above the vagina. Because of the location and short length of the female urethra, women are more likely to have bladder infections than men.

In men the urethra extends the full length of the penis. Infections of the lower urinary tract in men can occur with prostate infections.

Lower urinary system infections may spread to the kidneys, causing pyelonephritis. When you have a bladder infection, it is harder for your body to stop urine from flowing back to the kidneys. This makes it easier for infected urine to move into the kidneys.

The urinary system is a common site of birth defects. If your urinary system is abnormal, you have a greater risk that a bladder infection will spread to the kidneys.

If you have blockage from a kidney stone, you are at risk of developing pyelonephritis.

What are the symptoms?

The symptoms range from mild to severe. They may include:

Sometimes it is hard to know whether urinary symptoms are caused by an infection of the lower urinary tract (for example, the bladder) or by a kidney infection. The symptoms should not be ignored. If you have symptoms, see your healthcare provider right away. A bladder infection can quickly lead to pyelonephritis and infection in the bloodstream. Do not wait to get treatment.

How is it diagnosed?

Your healthcare provider will review your medical history, looking especially for current or recent lower urinary tract infection. You will also have a physical exam. Your provider will check for pain in the kidney area. A sample of your urine will be tested in the lab.

How is it treated?

Antibiotic medicine is the main treatment for a kidney infection. Your healthcare provider may treat you first as an outpatient. You may continue to be treated at home if your symptoms seem to be getting better 24 hours after you start taking the medicine. If you are more seriously ill or dehydrated, or the medicine does not seem to be working well, you may need to stay in the hospital. There you can be given fluids and medicine with an IV.

Usually you will need to take an antibiotic for at least 7 days. All bacteria must be killed to prevent kidney damage and to keep the infection from coming back.

Your antibiotic may need to be changed after the first day or two of treatment if lab tests of the bacteria in your urine show a different antibiotic will work better. Your healthcare provider will tell you if this is the case.

How long do the effects last?

How long it takes to get better depends on how severe your symptoms are when you start treatment. In mild cases, you will start feeling better in the first 1 or 2 days. It may take several days if you have a more severe infection.

With proper treatment there are few complications of pyelonephritis. If your symptoms come back soon after you finish your treatment, you may need more tests. Your healthcare provider will check for an underlying cause, such as a kidney stone.

How can I take care of myself?

How can I help prevent pyelonephritis?

Most cases of kidney infections in women result from bladder infections. The best way to prevent kidney infections is to try to prevent bladder infections. Ways women can try to prevent these infections are:

There are no specific preventive measures for men other than drinking plenty of fluids and practicing good genital hygiene. If you are a man who has not been circumcised, good hygiene includes gently pulling back the foreskin to wash the tip of the penis every time you bathe or shower.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File URIN5357.HTM Release 11.0/2008

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