Nephrotic syndrome can be caused by diseases that damage the kidneys. Some of these diseases affect only the kidneys, and these are called primary causes of nephrotic syndrome. Other diseases affect the whole body, including the kidneys, and these are called secondary causes of nephrotic syndrome. Most people who have nephrotic syndrome have secondary causes.

The most common primary cause of nephrotic syndrome in adults is a disease called focal segmental glomerulosclerosis (FSGS). FSGS causes scars on the kidneys’ tiny filters called glomeruli. The most common secondary cause of nephrotic syndrome in adults is diabetes.

The most common primary cause of nephrotic syndrome in children is minimal change disease. Minimal change disease causes kidney damage that can only be seen using a very powerful microscope. The most common secondary cause of nephrotic syndrome in children is diabetes.

Learn more about focal segmental glomerulosclerosis (FSGS) here.

Learn more about minimal change disease here.