How Diuretics Works

The The normal filtration process of the kidneys (which takes place in the tubules) removes water, salts (mainly potassium and sodium), and waste products from the bloodstream. Most of the salts and water are returned to the bloodstream, but certain amounts are expelled from the body together with the waste products in the urine.

Diuretics interfere with this normal kidney action. Osmotic, loop, and thiazide diuretics reduce the amount of sodium and water taken back into the blood, thus increasing the volume of urine. Modifying filtration in this way reduces the blood’s water content. Less water in the blood causes excess water in the tissues to be expelled in urine.