|Short description Overview and Benefits   Spironolactone is a water pill. It is a potassium-sparing diuretic used to prevent the body from taking in too much salt. The drug prevents the potassium levels from getting extremely low.   Spironolactone is also used in the diagnosis or treatment of the conditions of having too much aldosterone. Aldosterone is the hormone produced by the adrenal glands. It regulates the salt and water balance in the body.   Spironolactone can also be prescribed to treat edema (fluid retention) in patients with the cirrhosis of the liver, congestive heart failure as well as the nephrotic syndrome (a kidney disorder).