Glomerulonephritis

DEFINITION

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.

CAUSES

Many conditions can cause glomerulonephritis; however, sometimes the cause is unknown. Conditions that can lead to inflammation of the kidneys’ glomeruli may include:

Infections

• 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.

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 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.

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 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.

SYMPTOMS

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

When to see a doctor

Make an appointment with your doctor promptly if you have any signs or symptoms that concern you.