Glomerular diseases are among the most common renal pathologies leading 
frequently to end-stage renal disease. Clinical disease can be divided into five 
different groups the features of which are determined by the underlying 
pathophysiology. One of these five clinical syndromes is the nephrotic syndrome, 
which is characterized by proteinuria > 3.5 g/day accompanied by hypalbuminemia, 
hyperlipoproteinemia and pronounced edema. The nephrotic syndrome may be the 
clinical manifestation of a row of underlying diseases. The pathophysiological 
basics had remained elusive for decades, yet recently significant progress which 
allows for establishing new therapeutic strategies has been made. A major 
breakthrough in understanding the function of the glomerular filter unit has 
been possible in the last years through both genetic and cell biological 
studies, which have revealed a crucial role for the visceral epithelial cells of 
the glomerulus - the podocytes. By now various factors have been found causing 
podocyte damage, such as toxines, immunological phenomena or systemic disease 
like diabetes mellitus.