Glomerulonephritis (gloe-mer-u-low-nuh-FRY-tis) is inflammation of the tiny filters in your kidneys (glomeruli). Glomeruli remove excess fluid, electrolytes and waste from your bloodstream and pass them into your urine. 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. Severe or prolonged inflammation associated with glomerulonephritis can damage your kidneys. Treatment depends on the type of glomerulonephritis you have.
Signs and symptoms of glomerulonephritis 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.
Glomerulonephritis signs and symptoms may include:
- Pink or cola-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
Many conditions can cause glomerulonephritis; however, sometimes the cause is unknown. Conditions that can lead to inflammation of the kidneys’ glomeruli may include:
- Post-streptococcal glomerulonephritis. Glomerulonephritis may develop a week or two after recovery from a strep throat infection or, rarely, a skin infection (impetigo). To fight the infection, your body produces extra antibodies that may eventually settle in the glomeruli, causing inflammation. Children are more likely to develop post-streptococcal glomerulonephritis than are adults, and they’re also more likely to recover quickly.
- Bacterial endocarditis. Bacteria occasionally can spread through your bloodstream and lodge in your heart, causing an infection of one or more of your heart valves. You’re at greater risk of this condition if you have a heart defect, such as a damaged or artificial heart valve. Bacterial endocarditis is associated with glomerular disease, but the exact connection between the two is unclear.
- Viral infections. Viral infections, such as the human immunodeficiency virus (HIV), hepatitis B and hepatitis C, may trigger glomerulonephritis.
- 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 immunological lung disorder that may mimic pneumonia, Goodpasture’s syndrome causes bleeding in 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.
- 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 likely to cause scarring of the glomeruli
- High blood pressure. High blood pressure can damage your kidneys and impair their ability to function normally. Glomerulonephritis can also lead to high blood pressure because it reduces kidney function and may influence how your kidneys handle sodium.
- 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 kidney failure. Infrequently, chronic glomerulonephritis runs in families. One inherited form, Alport syndrome, also may involve hearing or vision impairment.
Glomerulonephritis can damage your kidneys so that they lose their filtering ability. As a result, dangerous levels of fluid, electrolytes and waste build up in your body.
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. You may need emergency dialysis — an artificial means of removing extra fluids and waste from your blood — typically by an artificial kidney machine.
- Chronic kidney disease. With chronic kidney disease, your kidneys gradually lose their filtering ability. If your kidney function deteriorates to less than 10 percent of normal capacity, you have end-stage kidney disease, which 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. With nephrotic syndrome, you have too much protein in your urine, which results in too little protein in your blood. Nephrotic syndrome may also be associated with high blood cholesterol and swelling (edema) of the eyelids, feet and abdomen.
Specific signs and symptoms may suggest glomerulonephritis, but the condition often comes to light when a routine urinalysis is abnormal. Tests to assess your kidney function and make a diagnosis of glomerulonephritis include:
- Urine test. A urinalysis may show red blood cells and red cell casts in your urine, an indicator of possible damage to the glomeruli. Urinalysis results may also show white blood cells, a common indicator of infection or inflammation, and increased protein, which may indicate nephron damage. Other indicators, such as increased blood levels of creatinine or urea, are red flags.
- Blood tests. These can provide information about kidney damage and impairment of the glomeruli 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.
Treatments and Medications:
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, tend to improve on their own and often require no specific treatment.
In general, the goal of treatment is to protect your kidneys from further damage.
Treatment for high blood pressure
Keeping your blood pressure under control is key to protecting your kidneys. To control your high blood pressure and slow the decline in kidney function, your doctor may prescribe one of several medications, including:
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers
Treatment for an underlying cause
If there’s an underlying cause for your kidney inflammation, your doctor may prescribe other drugs to treat the underlying problem, in addition to treatment to control any hypertension:
- Strep or other bacterial infection. Treatment usually focuses on easing your signs and symptoms. Your doctor also may prescribe an appropriate antibiotic.
- Lupus or vasculitis. Doctors often prescribe corticosteroids and immune-suppressing drugs to control inflammation.
- IgA nephropathy. In some cases, both fish oil supplements and certain immune-suppressing drugs can successfully treat certain people with IgA nephropathy. Researchers continue to investigate fish oil supplements for IgA nephropathy.
- 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 some of your plasma out of your blood and replacing it with other fluid or donated plasma.
Therapies for associated kidney failure
For acute glomerulonephritis and acute kidney failure, dialysis can help remove excess fluid and control high blood pressure. The only long-term therapies for end-stage kidney disease are kidney dialysis and kidney transplant. When a transplant isn’t possible, often because of poor general health, dialysis is the only option.