Diseases of the Urinogenital System - Nephritis

Nephritis is a disorder characterized by inflammation of the glomeruli of the kidneys. The glomeruli are tiny coiled blood vessels through which the liquid portion of the blood is filtered as it enters the outer structure of the kidneys. There are about one million of these tiny blood vessels in each kidney. The fluid from the blood passes from them into many little ducts called tubules . Water and various substances are secreted into and absorbed from the liquid in the tubules. The final product of this passage of filtered fluid from the glomeruli through the tubules to the ureters and then to the bladder is urine. It contains the excess fluid and waste products produced by the body during normal functioning.

When the glomeruli become inflamed, the resulting disease is called glomerulonephritis . There are several forms of this disease. One type is thought to be caused by the body's allergic reaction to infection by certain streptococcal bacteria. Another type sometimes accompanies infection of the valves of the heart. The relationship between glomerulonephritis and strep infections is not fully understood at present, and the same may be said for nephritis, which is associated with allergic reaction to certain drugs and to heart valve infections.

Glomerulonephritis may occur ten days to two weeks after a severe strep throat infection. For this reason, any severe sore throat accompanied by a high fever should be seen and diagnosed by a physician. Prompt treatment with antibiotics may decrease the possibility of kidney involvement.

Nephritis Symptoms

The inflammation and swelling of the glomeruli cause a decrease in the amount of blood that the kidney is able to filter. As a result of the slowing down of this kidney function, the waste products of metabolism as well as excess fluid accumulate in the body instead of being eliminated at the normal rate.

In a typical case, a person will develop a severe sore throat with fever and a general feeling of sickness. These symptoms will disappear, but after one or two weeks, there will be a return of weakness and loss of appetite. The eyes and the face may become puffy, the legs may swell, and there may be shortness of breath—all because of the retention of excess fluid in the body. The amount of urine is small and the color is dark brown, somewhat like coffee. Abdominal pain, nausea, and vomiting may occur, always accompanied by fatigue. In most cases, the blood pressure increases, leading to headaches.

Although there is a hereditary type of nephritis, the more common types of the disease have other causes. When the disease is suspected, the physician examines a specimen of urine under a microscope and looks for red blood cells. These cells, which usually do not pass through the walls of the normal glomerulus in large numbers, do pass through the damaged walls of the inflamed blood vessels characteristic of nephritis. Evidence of decreased kidney function is also found by special blood tests.

Nephritis occurs in all age groups. Children under ten have an excellent chance of recovery, about 98 percent. In adults, from 20 to 50 percent of the cases may be fatal or may progress to chronic nephritis, which often leads to uremia and death.

Treatment

It is absolutely essential for anyone with a streptococcal infection, which may lead to acute glomerulonephritis, to receive prompt and proper treatment. Penicillin is considered the most effective antibiotic at present.

Once acute nephritis is present, the treatment consists of bed rest, some fluid restriction, and protein restriction if kidney failure occurs. If there is a total loss of kidney function, a specially restricted diet is prescribed. Complete lack of urine output— anuria —may last as long as ten days, but the patient can still make a full recovery if the treatment is right. Usually a gradual return of kidney function occurs over a period of several months.