KIDNEY INFECTION, ACUTE

General Information

DEFINITION--A non-contagious bacterial infection of the kidneys (kidneys filter waste material from the bloodstream and produce urine).

BODY PARTS INVOLVED--Kidneys; urinary tract.

SEX OR AGE MOST AFFECTED--Both sexes, but more common in females of all ages. Acute kidney infections in males of any age may indicate a serious underlying disease, such as a tumor, obstruction or prostate disorder.

SIGNS & SYMPTOMS--

Sudden onset of:

• Fever and shaking chills.
• Burning, frequent urination.
• Cloudy urine or blood in the urine.
• Aching (sometimes severe) in one or both sides of the lower back.
• Abdominal pain.
• Marked fatigue. Note: Young children and the elderly may not have typical symptoms or signs.

CAUSES--

Bacteria (most commonly Escherichia coli) invade one or both kidneys. The infection may begin in the bladder. The most common sources of bacterial infection are:

• Vigorous sexual activity in women, which allows bacteria to enter the urethra and bladder.
• Infections elsewhere in the body that travel to the kidneys through the bloodstream or lymph glands.
• Blockage or abnormality of the urinary system, caused by stones, obstructions, bladder dysfunction from nerve diseases, tumors or congenital abnormalities.
• Catheters, tubes or surgical procedures used for other medical conditions.

RISK INCREASES WITH

• Diabetes mellitus.
• Chronic urinary-bladder infection or tumor.
• Infrequent emptying of urinary bladder.
• Paralysis from spinal-cord injury or tumor.
• Pregnancy.

HOW TO PREVENT--

No specific preventive measures for males. For females:

• After bowel movements, always wipe from the vaginal area toward the rectum.
• Avoid prolonged moistness around the urethra, such as that caused by nylon underpants or wet swim suits.
• Avoid sexual positions that irritate or hurt the urethra or bladder.
• Urinate within 15 minutes after sexual intercourse.
• Don't hold urine; when you have the urge to void, do so.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and physical exam by a doctor.
• Urinalysis and urine culture; cystoscopy, ultrasound, intravenous pyelogram (IVP) (See Glossary for all). Other special tests may be recommended.

APPROPRIATE HEALTH CARE

• Self-care after diagnosis.
• Doctor's treatment.

POSSIBLE COMPLICATIONS

• Chronic kidney infection.
• High blood pressure (hypertension).

PROBABLE OUTCOME--Usually curable in 10 to 14 days with treatment. Make a return doctor visit to assure complete cure.

How To Treat

GENERAL MEASURES--

• Avoid long periods without urinating (such as on a trip).
• Treatment for men may take longer in order to prevent a relapse.
• See Resources for Additional Information.

MEDICATION--Your doctor may prescribe:

• Oral antibiotics. Take all the antibiotics prescribed, even if symptoms disappear.
• Antibiotics (intravenous or by injection), if oral antibiotics don't cure the infection.
• Urinary analgesics to relieve pain.

ACTIVITY--Rest in bed until high fever and discomfort subside. Don't resume sexual relations until fever or urinary symptoms have cleared.

DIET--No special diet. Drink at least 2 quarts of liquid daily; include cranberry juice or vitamin C to acidify the urine.

Call Your Doctor If

• You have symptoms of a kidney infection.
• The following occurs during treatment: Symptoms and fever persist after 48 hours of antibiotic treatment. Occasionally a different antibiotic is needed. Symptoms return (especially if accompanied by fever) after antibiotic treatment.
• New, unexplained symptoms develop. Drugs used in treatment may produce side effects.