(See also Overview of Glomerular Disorders Overview of Glomerular Disorders The hallmark of glomerular disorders is proteinuria, which is often in the nephrotic range (≥ 3 g/day). Glomerular disorders are classified based on urine changes as those that manifest predominantly... read more .)
Nephritic syndrome is a manifestation of glomerular inflammation (glomerulonephritis) and occurs at any age. Causes differ by age (see table Glomerular Disorders by Age and Presentation Glomerular Disorders by Age and Manifestations The hallmark of glomerular disorders is proteinuria, which is often in the nephrotic range (≥ 3 g/day). Glomerular disorders are classified based on urine changes as those that manifest predominantly... read more ), and mechanisms differ by cause. The syndrome can be
Acute (serum creatinine rises over many weeks or less)
Chronic (renal insufficiency may progress over years)
Nephritic syndrome can also be
Primary (idiopathic)
Secondary
Acute glomerulonephritis
Postinfectious glomerulonephritis Postinfectious Glomerulonephritis (PIGN) Postinfectious glomerulonephritis occurs after infection, usually with a nephritogenic strain of group A beta-hemolytic streptococcus. Diagnosis is suggested by history and urinalysis and confirmed... read more 
is the prototype of acute glomerulonephritis, but the condition may be caused by other glomerulopathies and by systemic disorders such as connective tissue disorders and hematologic dyscrasias (see table Causes of Glomerulonephritis Causes of Glomerulonephritis Nephritic syndrome is defined by hematuria, variable degrees of proteinuria, usually dysmorphic red blood cells (RBCs), and often RBC casts on microscopic examination of urinary sediment. Often... read more ).
Rapidly progressive glomerulonephritis Rapidly Progressive Glomerulonephritis (RPGN) Rapidly progressive glomerulonephritis is acute nephritic syndrome accompanied by microscopic glomerular crescent formation with progression to renal failure within weeks to months. Diagnosis... read more 
(RPGN) is an acute glomerulonephritis resulting from the secondary sequelae of inflammatory (crescenteric) glomerulonephritis, of which there are many causes. RPGN is a pathologic diagnosis.
Chronic glomerulonephritis
Chronic glomerulonephritis has features similar to those of acute glomerulonephritis but develops slowly and may cause mild to moderate proteinuria. Examples include
