​Nephrotic syndrome can be primary, meaning damage is confined to the kidneys alone,
or it can be secondary, meaning organs other than the kidney are also affected.

Primary causes

• Minimal change disease (MCD) is a kidney disease that can occur in both adults and
  children The disease gets its name because the damage to the glomeruli cannot be
  seen under a regular microscope and can only be seen under a powerful microscope
  called an electron microscope
  
  
• Focal segmental glomerulosclerosis (FSGS) is the most common cause of nephrotic
  syndrome in adults. FSGS can cause collapse and scarring of some glomeruli
  Membranous nephropathy (MN) is a condition in which the walls of the glomerular
  blood vessels become thickened

Secondary causes

• Diabetes mellitus causing diabetic kidney disease is common in patients with diabetes
  who have chronically elevated blood glucose levels and/or high blood pressure
  Patients with more advanced disease can develop the nephrotic syndrome
  
  
• Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect multiple
  organs of the body, including the kidney, causing nephrotic syndrome