Berger's disease or IgA nephropathy is a common form of glomerulonephritis that falls under the broad diagnostic category of primary glomerulonephritis. Diagnosis is made by clinical presentation and morphological changes noted on a biopsy of renal tissue. The exact cause is not known. The literature does implicate an immune-complex mediated syndrome and/or a defect in mucosal immunity as possible pathogenic mechanisms. With the advances made in diagnostic techniques, IgA nephropathy is now recognized as the most common type of glomerulonephritis in the world.