[The glomerulus in all its states]

Glomerulonephritis are the result of an inflammatory hit to the glomerulus. They are rare and heterogeneous renal diseases. Each glomerular compartment can be affected. The clinical manifestations present with hematuria, proteinuria and/or impaired renal function, either isolated or combined. Two main clinico-biological syndromes are described: nephrotic syndrome and nephritic syndrome. The latter can present in a more severe form i.e. rapidly progressive glomerulonephritis with the worst prognosis. These different clinical pictures are related to specific glomerular lesions. Thus, podocytic damage is mainly responsible for nephrotic syndromes, mesangial damage is responsible for proteinuria and hematuria and, finally, endothelial damage is responsible for nephritic syndrome and rapidly progressive glomerulonephritis. Therapeutic approaches include non-specific measures, combining both life-style and pharmacological interventions with the aim to reduce risk factors, and specific measures with the use of different immunosuppressive agents.