Answer. Glomerulonephritis (gloh-MAIR-yoo-loh-neh-FRY-tis) is actually several diseases that cause damage to the tiny blood vessels in the kidneys that filter out waste products and excess fluid from the blood stream.  In the early stages, most of these diseases have no symptoms. Sometimes damage to these tiny filters causes dark brown urine or blood in the urine that you can see. Most often, small amounts of blood in the urine can only be seen under a microscope. Glomerulonephritis can also cause protein from the blood stream to be found in the urine. We often call swelling of the legs or puffiness around the eyes from the loss of protein in the urine nephrotic syndrome. When the doctor finds blood or protein in the urine, she or he will do blood and urine tests to try to find the cause. Sometimes, special x-ray tests are done and a kidney biopsy may be needed to tell what disease is causing damage to the kidney filters.

When glomerulonephritis develops suddenly, we call it acute glomerulonephritis. This kind of glomerulonephritis is often the result of an infection, like a Strep throat or a Strep skin infection. Children who have glomerulonephritis after an infection often get better on their own. Some kinds of acute glomerulonephritis get better with medications, but some can also cause kidney failure.

Sometimes glomerulonephritis develops slowly, and it gradually begins to damage the kidney filters. We call this form chronic glomerulonephritis and it sometimes results in kidney failure. Often the cause of chronic glomerulonephritis is not found, but a kidney biopsy may help us to know what medications or other treatments are likely to be the most effective in preventing kidney function from getting worse.

It is hard to prevent glomerulonephritis, because we do not know many of the exact causes. Preventing infections, using protection during sex and not using IV drugs may prevent some of the infections that can cause glomerulonephritis.

Some specific medicines are used to slow down the chronic form of glomerulonephritis. Most of these medications suppress the immune system that seems to be attacking the kidneys. Since high blood pressure further damages the kidneys, very good control of blood pressure with certain medicines is helpful in slowing down damage to the kidneys. Recently, lowering the cholesterol with medication has shown to decrease the amount of protein in the urine and slow down kidney damage in patients with chronic glomerulonephritis.

Answer provided by George Aronoff, MD, FACP. Dr. Aronoff is Professor of Medicine and Pharmacology and Chief, Division of Nephrology at the University of Louisville School of Medicine, Louisville, Kentucky. He is also a member of the AAKP Medical Advisory Board.

The American Association of Kidney Patients presents Ask the Doctor, an opportunity for readers to submit kidney related health questions to healthcare professionals who specialize in an area of concern. The answers are not to be construed as a diagnosis and therefore, alterations in current healthcare should not occur until the patient’s physician is consulted.

This article originally appeared in the March/April 2004 issue of Kidney Beginnings: The Magazine, Vol. 3, No. 1.

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