What is the most common cause of nephrotic syndrome in adults?

The most common cause of nephrotic syndrome in adults is membranous nephropathy. This condition is characterized by the presence of immune complex deposition along the glomerular basement membrane, leading to increased permeability and the subsequent loss of protein in the urine. In adults, membranous nephropathy accounts for a significant percentage of nephrotic syndrome cases, making it a prominent cause that physicians encounter when evaluating adult patients with this condition.

Diabetes mellitus is a well-known cause of nephropathy and can lead to nephrotic syndrome through diabetic kidney disease, but it is more typically associated with nephritic syndrome or progressive kidney disease rather than presenting primarily with nephrotic syndrome. Minimal change disease and focal segmental glomerulosclerosis are also causes of nephrotic syndrome but are more commonly seen in children or in specific demographic groups within adults. Membranous nephropathy's prevalence in the broader adult population highlights its significance as the leading cause of nephrotic syndrome in this demographic.