Glomerulonephritis is a type of kidney disease in which there is inflammation of the glomeruli, the tiny filters that remove excess waste and fluids from the blood. It may be acute or chronic (coming on gradually), and may occur on its own (primary) or be caused by another condition (secondary). Signs and symptoms may depend on the type and cause of the condition and may include blood in the urine; foamy urine; swelling of the face, eyes, or other body parts; abdominal pain; high blood pressure; fatigue; and/or other symptoms. If the condition is severe or prolonged, the kidneys can become damaged. It may be caused by a variety of infections and diseases, and sometimes the cause is unknown.