Diuretic Diuretics are substances that cause an increase of the amount of water and sodium that is excreted in the urine. (1)Xiaoping Du. Diuretics. Available here. Related articles Do the elderly become less sensitive to the sense of thirst? Is coffee or tea a diuretic? Is “8 glasses of water per day” a myth? References [ + ] 1. ↑ Xiaoping Du. Diuretics. Available here.