A group of disorders that cause inflammation of the internal kidney structures (specifically, the glomeruli).

Acute nephritic syndrome is the result of inflammation of the internal structures of the kidney, often caused by unknown factors(such as seen in Henoch-Schonlein prupura) or an immune response triggered by infection or disease (typified by acutepost-streptococcal glomerulonephritis). Frequently observed symptoms and signs include changes in urine volume (decreased), protein in urine (protinuria), microscopic or gross blood in urine (hematuria) ,swelling (edema) , high blood pressure (hypertension) and a decreased ability of the kidney to remove wastes effectively.Associated diseases generally seen more frequently in children and adolescents:- IgA nephropathy- Henoch-Schonlein purpura- hemolytic uremic syndrome- post-streptococcal glomerulonephritis- glue sniffing; gasoline inhalation- bacterial infection or sepsisAssociated diseases generally seen more frequently in adults:- SLE ; lupus nephritis- membranoproliferative GN I- membranoproliferative GN II- infective endocarditis- vasculitis- rapidly progressive (crescentic) glomerulonephritis- Goodpasture's syndrome- Klebsiella pneumonia- abdominal abscesses- viral diseases: mononucleosis, measles, mumps, and so on- typhoid fever- hepatitis- syphilis and other sexually transmitted diseasesInflammation disrupts the functioning of the glomerulus, which is the part of the kidney that controls filtering and excretion.Inefficient glomerular functioning results in the loss of blood and protein in the urine and the accumulation of excess fluid inthe body. Swelling results when protein is lost from the blood stream. (Protein maintains fluid within the blood vessels, andwhen it is lost the fluid collects in the tissues of the body).Urine discoloration results from blood in the urine . This occurs because of loss of blood within the damaged glomeruli.Acute nephritic syndrome may be associated with the development of hypertension, interstitial inflammation (inflammation ofthe spaces between the cells of the kidney tissue), and acute renal failure .The disorder is uncommon, affecting 4 out of 100,000 persons. It affects both sexes and is evenly distributed across age groups.

Many times the disorder cannot be prevented, although treatment of illness and infection may help to reduce the risk.