The kidneys are technically like certain other internal organs; for example, the uterus, the lungs, and the gastrointestinal tract, which are open to the outside. They can, under certain circumstances, become infected with outside organisms. They can be infected from the inside by blood-borne organisms. When they do become infected, this can be a very serious condition. In the worst case scenario, they can become scarred and dysfunctional or even destroyed if the infection is serious enough. Physicians must remain attuned to the possibility of kidney infection when evaluating acute or chronic illness.
The term “kidney infection” is often used as a generic term to describe an infection anywhere within the genitourinary system. In actuality more specific terms should be used. Urethritis is an infection of the urethral tube which runs from the bladder to the outside urinary opening. Prostatitis is an infection of the male gland located at the base of the bladder. Cystitis is an infection of the bladder. Pyelonephritis is the occurrence of infection in the actual structure of the kidney. Technically, a kidney infection should be referred to as pyelonephritis. It is a very severe issue
The kidney usually protects itself by, in addition to the immune defense system, the continuous flow of urine out of the kidney down the ureter. Bacteria are not able to travel upstream when the anatomy is correct. There is a valve where the ureter joins the bladder that keeps urine from going back up the ureter when the bladder contracts. There are anatomical problems which can occur and predispose to infection. Sometimes the ureter-bladder valves don’t work right, and urine travels up the ureter to the kidney when the bladder contracts.
Sometimes there can be a stone in the ureter which blocks the continuous flow out of the kidney. The ureters in pregnant women tend to enlarge due to hormonal effects, and the flow down the ureter is less brisk. In other cases, an immune system is weakened, as in pregnancy, diabetes, and HIV, allowing bacteria to survive where they otherwise would not survive. The immune systems in infants, especially pre-term infants, are under-developed and may allow infections to occur.
The signs of a kidney infection, or pyelonephritis, may be severe in acute cases, or not as severe in chronic cases as in diabetics. An acute kidney infection usually prompts a fever to around 102, which may not come down with acetaminophen. There may be pain to a light kidney punch over the affected kidney. There is often burning with urination which often occurs more frequently and in smaller amounts. There may be blood or discoloration in the urine, which may have a foul smell to it. It is not uncommon to have nausea and vomiting, and some degree of dehydration. Acute kidney infection can even present with delirium. The diagnosis can be tricky in young children who cannot describe their symptoms, and who just appear very sick.
The physician will order a urinalysis when he suspects a urinary tract infection, and will usually ask the lab to do a bacterial culture and antibiotic sensitivity. A lot of germs in the urinary tract may be resistant to certain commonly used antibiotics. Analyzing the urine will yield a lot of information. It will reveal if there are white blood cells, red blood cells, and bacteria in the urine. It will show if the person is dehydrated. The nitrite test is very sensitive to bacterial infection. The physician will probably order a complete blood count and chemistry to assess kidney function tests and the state of hydration. Frequently a dehydrated patient with urinary tract infection will have to be admitted to the hospital for intravenous fluids and antibiotics. Once the hydration and infection are coming under control, the patient may be switched to oral fluids and oral antibiotics. If this transition proceeds smoothly, the patient may be discharged home on oral antibiotics. Full treatment of a kidney infection may require up to twenty days of antibiotics. It is so important that antibiotics be taken for a full course, and that a follow-up urinalysis shows the post-treatment urine to be sterile as it should be.
There are some practices which can improve overall urinary health and hopefully prevent kidney infections. Drinking at least six glasses of water per day keeps the urine flowing at a satisfactory rate. If a female is getting bouts of cystitis, it may be necessary to forego tub bathing in favor of showers. Drinking cranberry juice hasn’t been shown conclusively to prevent infections, but it may slightly help. Emptying the bladder regularly and not letting it get over-distended is a good practice, and emptying the bladder after sexual relations is important to prevent cystitis. Post-toilet wiping of the genital area should be practiced front to back in motion. Concerning the immune system, it is so important for diabetics to keep blood sugar under good control, and be checked periodically for urinary function. Likewise pregnant women should understand that they are predisposed to infection, and should keep regular prenatal visits.
The kidneys are marvels of compactness and unbelievable efficiency in the health of a human being. They must be protected and cared for with reverence and respect. Quality of life is inextricably altered when the kidneys begin to malfunction. Practice good urinary health, and work with your physician to be sure all problems, large and small, are appropriately treated. When in doubt or with any symptoms see your M.D.
John Drew Laurusonis
Doctors Medical Center