Nephrotic syndrome is uncommon in general practice. A GP may only see two or three adult cases in their career. Nephrotic syndrome develops following pathological injury to renal glomeruli. This may be a primary problem, with a disease specific to the kidneys, or secondary to a systemic disorder such as diabetes mellitus. The most common cause in children is minimal change glomerulonephritis. In white adults, nephrotic syndrome is most frequently due to membranous nephropathy whereas in populations of African ancestry the most common cause of nephrotic syndrome is focal segmental glomerulosclerosis (FSGS). Diabetic nephropathy is the most common multisystem disease that can cause nephrotic syndrome.