Glomerulonephritis is a progressive kidney disease that involves the glomeruli, the individual filtering units of the kidney that produce urine. When the glomeruli become inflamed, the kidneys can't filter urine properly. This results in a buildup of excess fluid and toxins in the body. Glomerulonephritis can lead to chronic renal (kidney) failure.
There are two main types of glomerulonephritis: primary and secondary. Primary glomerulonephritis affects the kidneys directly, while in secondary glomerulonephritis the kidneys are damaged as a result of another illness. Glomerulonephritis seems to happen twice as often in males as in females.
Most people with glomerulonephritis have no known cause or risk factors.
The most common known causes are bacterial (most often streptococcal) and viral infections. Doctors have found that many children with glomerulonephritis had been diagnosed with a streptococcal infection, such as strep throat, not long before developing signs of kidney damage. People with hepatitis or HIV/AIDS can also develop glomerulonephritis.
People with autoimmune disorders, such as lupus, also seem to be at risk of developing glomerulonephritis. The immune system, instead of attacking bacteria or viruses, attacks the kidneys so that they can't function properly.