Black coffee has the effect of diuretic and edema removal. Black coffee contains the highest caffeine, which can bind with the anti-diuretic hormone secreted by the hypothalamus, thus preventing the secretion of anti-diuretic hormone in the body, and the anti-diuretic hormone can enhance the reabsorption of water by the renal tubules and collecting ducts. Therefore, when antidiuretic hormone is antagonized by caffeine in black coffee, diuretic effect will occur, and the diuretic will be able to remove excess water from the body, so it will remove edema. In addition, black coffee also contains a certain amount of cocoa, cocoa is also has a certain diuretic effect. Therefore, the role of black coffee for diuretic and edema is clear and obvious, but the diuretic way through black coffee is not advisable, because excessive intake of black coffee will make the body’s nerve center overexcited.