Pyelonephritis (Kidney Infection) in Adults

Pyelonephritis is a kidney infection, usually from bacteria that have spread from the bladder.

Possible causes of infection include the following:

• infections in the bladder
• use of a catheter to drain urine from the bladder
• use of a cystoscope to examine the bladder and urethra
• surgery on the urinary tract
• conditions such as prostate enlargement and kidney stones that prevent the efficient flow of urine from the bladder

Symptoms and signs include back, side, and groin pain; urgent, frequent urination; pain or burning during urination; fever; nausea and vomiting; and pus and blood in the urine.

Diagnosis is made with a urine test to identify bacteria and formations of white blood cells, called casts, shaped like tubes in the kidneys. If an infection cannot be easily cured, x rays might be done to look for abnormalities in the kidneys, ureters, and bladder. A kidney infection is treated with an appropriate antibiotic, and abnormalities may need to be surgically treated.

An untreated or recurrent kidney infection can lead to chronic pyelonephritis, scarring of the kidneys, and permanent kidney damage.