Introduction



Kidney infection (pyelonephritis) is a specific type of urinary tract infection (UTI) that generally begins in your urethra or bladder and travels up into your kidneys. If not treated properly, kidney infection can permanently damage your kidneys or spread to your bloodstream and cause a life-threatening infection. Prompt medical attention is required.

Your kidneys filter waste from your blood, adjust blood levels of many substances, and conserve or excrete water from your system depending on your body's needs. Urine is the product of this filtration and renal tubular function.

WHAT YOU SHOULD KNOW

Known medically as pyelonephritis (PI-low-nef-RI-tis), kidney infections usually start in the bladder. If your resistance is low, germs from the bladder can travel up the tubes (ureters) that lead to the kidneys, take up residence, and multiply. An acute kidney infection starts suddenly with severe symptoms, then quickly comes to an end. A chronic kidney infection develops slowly, grows steadily worse, and hangs on. The chronic variety can lead to kidney failure.

What are the causes of UTI?

Normally, urine is sterile. It is usually free of bacteria, viruses, and fungi but does contain fluids, salts, and waste products. An infection occurs when tiny organisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. The urethra is the tube that carries urine from the bladder to outside the body. Most infections arise from one type of bacteria, Escherichia coli (E. coli), which normally lives in the colon.

Symptoms   

Flank pain or back pain

·    Severe abdominal pain (occurs occasionally)

·    Fever

·    Chills with shaking

·    Warm skin

·    Flushed or reddened skin

·    Moist skin (diaphoresis)

·    Vomiting, nausea

·    Fatigue

·    General ill feeling

·    Painful urination

·    Increased urinary frequency or urgency

·    Need to urinate at night (nocturia)

·    Cloudy or abnormal urine color

·    Blood in the urine

·    Foul or strong urine odor

·    Mental changes or confusion

What causes a kidney infection?

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

A common source of infection is catheters, or tubes, placed in the bladder. A person who cannot void, is unconscious, or is critically ill, often needs a catheter that stays in place for a long time. Some people, especially the elderly or those with nervous system disorders who lose bladder control, may need a catheter for life. Bacteria on the catheter can infect the bladder, so hospital staff take special care to keep the catheter sterile and remove it as soon as possible.

Symptoms

Symptoms of pyelonephritis often begin suddenly with chills, fever, pain in the lower part of the back on either side, nausea, and vomiting.

About one third of people with pyelonephritis also have symptoms of cystitis, including frequent, painful urination. One or both kidneys may be enlarged and painful, and doctors may find tenderness in the small of the back on the affected side. Sometimes the muscles of the abdomen are tightly contracted. Irritation from the infection or the passing of a kidney stone (if one is present) can cause spasms of the ureters.