Causes

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:

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 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.

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 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.

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.
• 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.