Click to Enlarge

Kidney cross section

Glomerulonephritis (glo-mer-u-lo-nuh-FRI-tis) is a type of kidney disease that damages your kidneys' ability to remove waste and excess fluids. Also called glomerular disease, glomerulonephritis can be acute — a sudden attack of inflammation — or chronic — coming on gradually.

If glomerulonephritis occurs on its own, it's known as primary glomerulonephritis. If another disease, such as lupus or diabetes, is the cause, it's called secondary glomerulonephritis. Treatment depends on the type of glomerulonephritis you have.

Signs and symptoms of glomerulonephritis may depend on whether you have the acute or chronic form, and the cause. Your first indication that something is wrong may come from symptoms or from the results of a routine urinalysis. Signs and symptoms may include:

• Cola-colored or diluted, iced-tea-colored urine from red blood cells in your urine (hematuria)
• Foamy urine due to excess protein (proteinuria)
• High blood pressure (hypertension)
• Fluid retention (edema) with swelling evident in your face, hands, feet and abdomen
• Fatigue from anemia or kidney failure
• Less frequent urination than usual

When to see a doctor
Make an appointment with your doctor if you have a condition that's associated with glomerulonephritis. Make an appointment promptly if you're experiencing any of the signs or symptoms of glomerulonephritis.

Click to Enlarge

Kidney cross section

Each of your kidneys contains approximately 1 million tiny filters (glomeruli), which attach to the opening of a small fluid-collecting tube (tubule). Each glomerulus and tubule form a nephron, the functional unit of the kidneys. The glomeruli filter your blood as it passes through your kidneys, and the filtered blood returns to your bloodstream. The tubules modify what the glomeruli filter by saving needed substances, such as protein. The waste goes to your bladder as urine through a tube (ureter) from each kidney and passes out of your body when you urinate.

Glomerulonephritis — an inflammation of the glomeruli — can damage your kidneys so that they lose their filtering ability, allowing dangerous levels of fluid and waste to accumulate in your body (called kidney failure) and depriving your bloodstream of protein, which is excreted in your urine.

Often the cause of glomerulonephritis is unknown. Known causes include:

Infections

• Post-streptococcal glomerulonephritis. Glomerulonephritis may develop after a strep infection in your throat or, rarely, on your skin (impetigo). Post-infectious glomerulonephritis is becoming less common in the United States, most likely because of rapid and complete antibiotic treatment of most streptococcal infections.
• Bacterial endocarditis. Bacteria can occasionally spread through your bloodstream and lodge in your heart, causing an infection of one or more of your heart valves. Those at greatest risk are people with a heart defect, such as a damaged or artificial heart valve.
• Viral infections. Among the viral infections that may trigger glomerulonephritis are the human immunodeficiency virus (HIV), which causes AIDS, and the hepatitis B and hepatitis C viruses, which primarily affect the liver.

Immune diseases

• Lupus. A chronic inflammatory disease, lupus can affect many parts of your body, including your skin, joints, kidneys, blood cells, heart and lungs.
• Goodpasture's syndrome. A rare immune lung disorder that may mimic pneumonia, Goodpasture's syndrome causes bleeding (hemorrhage) into your lungs as well as glomerulonephritis.
• IgA nephropathy. Characterized by recurrent episodes of blood in the urine, this primary glomerular disease results from deposits of immunoglobulin A (IgA) in the glomeruli. IgA nephropathy can progress for years with no noticeable symptoms. The disorder seems to be more common in men than in women.

Vasculitis

• Polyarteritis. This form of vasculitis affects small and medium blood vessels in many parts of your body, such as your heart, kidneys and intestines.
• Wegener's granulomatosis. This form of vasculitis affects small and medium blood vessels in your lungs, upper airways and kidneys.

Conditions that cause scarring of the glomeruli

• High blood pressure. Damage to your kidneys and their ability to perform their normal functions can occur as a result of high blood pressure. Glomerulonephritis can also cause high blood pressure because it reduces kidney function.
• Diabetic kidney disease. Diabetic kidney disease (diabetic nephropathy) can affect anyone with diabetes. Diabetic nephropathy usually takes years to develop. Good control of blood sugar levels and blood pressure may prevent or slow kidney damage.
• Focal segmental glomerulosclerosis. Characterized by scattered scarring of some of the glomeruli, this condition may result from another disease or occur for no known reason.

Chronic glomerulonephritis sometimes develops after a bout of acute glomerulonephritis. In some people there's no history of kidney disease, so the first indication of chronic glomerulonephritis is chronic kidney failure. Infrequently, chronic glomerulonephritis runs in families. One inherited form, Alport syndrome, may also involve hearing or vision impairment.

Complications of glomerulonephritis may include:

• Acute kidney failure. Loss of function in the filtering part of the nephron may cause waste products to accumulate rapidly. This condition may mean you'll need emergency dialysis, an artificial means of removing extra fluids and waste from your blood, typically by an artificial kidney machine (dialyzer).
• Chronic kidney failure. In this extremely serious complication, the kidneys gradually lose function. Kidney function at less than 10 percent of normal capacity indicates end-stage kidney disease, which usually requires dialysis or a kidney transplant to sustain life.
• High blood pressure. Damage to your kidneys and the resulting buildup of wastes in the bloodstream can raise your blood pressure.
• Nephrotic syndrome. This is a group of signs and symptoms that may accompany glomerulonephritis and other conditions that affect the filtering ability of the glomeruli. Nephrotic syndrome is characterized by high protein levels in the urine, resulting in low protein levels in the blood; high blood cholesterol; and swelling from fluid retention (edema) of the eyelids, feet and abdomen.

You're likely to start by first seeing your family doctor or a primary care professional. However, in some cases when you call to set up an appointment, you may be referred immediately to a kidney specialist (nephrologist).

To be sure you get the information you need, you can prepare for your appointment.

What you can do

• Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Write down the symptoms you're having, even if they seem unrelated to the reason for your appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins and supplements that you're taking.
• Take a companion along, if possible. Someone who accompanies you can help you remember the information you get from your doctor.
• Write down questions you want answered.

List your questions from most important to least important in case time runs out. For glomerulonephritis, some basic questions to ask your doctor include:

• How badly are my kidneys affected?
• What kinds of tests do I need?
• Is my condition likely temporary or chronic?
• Will I need dialysis?
• What restrictions do I need to follow?
• Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist?
• Is there a generic alternative to the medicine you're prescribing me?
• Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend visiting?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

Specific signs and symptoms may suggest glomerulonephritis, but the condition often comes to light when a routine urinalysis is abnormal. The urinalysis may show:

• Red blood cells and red cell casts, an indicator of possible damage to the glomeruli
• White blood cells, a common indicator of infection or inflammation
• Increased protein, which may indicate nephron damage

Other indicators, such as increased blood levels of creatinine or urea, also are red flags. Or, your hard-to-control high blood pressure may cause your doctor to suspect glomerulonephritis.

If your doctor suspects glomerulonephritis, you may undergo one or more of the following diagnostic procedures, in addition to urine testing:

• Blood tests. These can provide information about kidney damage and impairment of the filtering mechanisms by measuring levels of waste products, such as creatinine and blood urea nitrogen.
• Imaging tests. If your doctor detects evidence of damage, he or she may recommend diagnostic studies that allow visualization of your kidneys, such as a kidney X-ray, an ultrasound examination or a computerized tomography (CT) scan.
• Kidney biopsy. This procedure involves using a special needle to extract small pieces of kidney tissue for microscopic examination to help determine the cause of the inflammation. A kidney biopsy is almost always necessary to confirm a diagnosis of glomerulonephritis.

Treatment of glomerulonephritis and your outcome depend on:

• Whether you have an acute or chronic form of the disease
• The underlying cause
• The type and severity of your signs and symptoms

Some cases of acute glomerulonephritis, especially those that follow a strep infection, often improve on their own and require no specific treatment.

To control your high blood pressure and slow the decline in kidney function, your doctor may prescribe one of several medications, including:

• Diuretics
• Angiotensin-converting enzyme (ACE) inhibitors
• Angiotensin II receptor agonists

Your doctor also may prescribe other drugs to treat the underlying cause of glomerulonephritis:

• Strep or other bacterial infection. Your doctor likely will prescribe an appropriate antibiotic.
• Lupus or vasculitis. Doctors often prescribe corticosteroids and immune-suppressing drugs.
• IgA nephropathy. Fish oil supplements have been successful in some people with IgA nephropathy and are under study.
• Goodpasture's syndrome. Plasmapheresis is sometimes used to treat people with Goodpasture's syndrome. Plasmapheresis is a mechanical process that removes antibodies from your blood by taking the plasma out of your blood and replacing it with fluid or donated plasma.

Therapies for associated kidney failure
For acute glomerulonephritis and acute kidney failure, temporary dialysis can help remove excess fluid and control high blood pressure. The only long-term therapies for end-stage kidney failure are kidney dialysis and kidney transplantation. When a transplant isn't possible, often because of poor general health, dialysis becomes the only option.

Your doctor may recommend changes in your diet, including:

• Restricting salt intake to prevent or minimize fluid retention, swelling and hypertension
• Cutting back on protein and potassium consumption to slow the buildup of wastes in your blood

If you have diabetes, the following may help slow kidney damage:

• Maintain a healthy weight
• Control your blood sugar level

Because living with chronic glomerulonephritis and chronic kidney failure can tax your emotional resources, you might benefit from joining a support group. Such a group can provide both sympathetic listening and useful information. To find out about support groups in your area that deal with kidney disease, ask your doctor or contact the National Kidney Foundation to find the chapter nearest you.

There's no way to prevent most forms of glomerulonephritis. However, here are some steps that may be beneficial:

• Seek prompt treatment of a strep infection causing a sore throat or impetigo.
• To prevent infections, such as HIV and hepatitis, that can lead to some forms of glomerulonephritis, follow safe-sex guidelines and avoid intravenous drug use.
• Control your blood sugar to help prevent diabetic nephropathy.
• Control your blood pressure, which lessens the likelihood of damage to your kidneys from hypertension.