Spironolactone blocks the action of the hormone aldosterone in the body. This causes salt and water loss from the blood vessels. The water then leaves the body in your urine. Your blood vessels are like pipes that carry blood throughout your body. The more fluid there is inside your blood vessels, the higher the pressure. The less fluid there is inside, the lower the pressure.
Spironolactone also relaxes the blood vessel walls. When the blood vessel walls relax it is easier to pump blood through them. This also lowers blood pressure.
Lowering aldosterone in the body also helps the heart directly. It helps the heart in ways that are different from lowering blood pressure. Taking spironolactone lowers the chance of heart failure that is caused by thick heart muscles.
Less Pressure, More Health!