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. Glomerulonephritis can come on suddenly (acute) or gradually (chronic).
Glomerulonephritis occurs on its own or as part of another disease, such as lupus or diabetes. 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 might come from symptoms or from the results of a routine urinalysis.
Glomerulonephritis signs and symptoms 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
When to see a doctor
Make an appointment with your doctor promptly if you have signs or symptoms that concern you.
Many conditions can cause glomerulonephritis. Sometimes the disease runs in families and sometimes the cause is unknown. Conditions that can lead to inflammation of the kidneys' glomeruli 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 can 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 connection between the two is unclear.
- Viral infections. Viral infections, such as the human immunodeficiency virus (HIV), hepatitis B and hepatitis C, can 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 can 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.
- Granulomatosis with polyangiitis. This form of vasculitis, formerly known as Wegener's granulomatosis, affects small and medium blood vessels in your lungs, upper airways and kidneys.
Conditions likely to cause scarring of the glomeruli
- High blood pressure. This 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 can influence how your kidneys handle sodium.
- Diabetic kidney disease (diabetic nephropathy). This can affect anyone with diabetes, usually taking years to develop. Good control of blood sugar levels and blood pressure might prevent or slow kidney damage.
- Focal segmental glomerulosclerosis. Characterized by scattered scarring of some of the glomeruli, this condition can result from another disease or occur for no known reason.
Infrequently, chronic glomerulonephritis runs in families. One inherited form, Alport syndrome, also might impair hearing or vision.
In addition to the causes listed above, glomerulonephritis is associated with certain cancers, such as multiple myeloma, lung cancer and chronic lymphocytic leukemia.
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.
Possible complications of glomerulonephritis include:
- Acute kidney failure. Loss of function in the filtering part of the nephron can result in rapid accumulation of waste products. You might need emergency dialysis — an artificial means of removing extra fluids and waste from your blood — typically by an artificial kidney machine.
- Chronic kidney disease. Your kidneys gradually lose their filtering ability. Kidney function that deteriorates to less than 10 percent of normal capacity results in 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 this syndrome, too much protein in your urine results in too little protein in your blood. Nephrotic syndrome can be associated with high blood cholesterol and swelling (edema) of the eyelids, feet and abdomen.
There may be no way to prevent most forms of glomerulonephritis. However, here are some steps that might be beneficial:
- Seek prompt treatment of a strep infection with a sore throat or impetigo.
- To prevent infections that can lead to some forms of glomerulonephritis, such as HIV and hepatitis, follow safe-sex guidelines and avoid intravenous drug use.
- Control high blood pressure, which lessens the likelihood of damage to your kidneys from hypertension.
- Control your blood sugar to help prevent diabetic nephropathy.