Diuretics are very widely used in clinical practice. Diuretics mainly act on the kidneys to promote the excretion of sodium and chloride ions and water in the body, thus increasing urine output and eliminating edema in the body. The main mechanism of action of diuretics is to act on the renal tubules to promote the excretion of large amounts of sodium, chloride ions and water through the ion channels of the renal tubules, thereby increasing urine output. Depending on the site of action and the diuretic effect, diuretics can be divided into the following categories: 1) high-efficiency diuretics, represented by furosemide. 2) medium-acting diuretics, represented by thiazides, such as hydrochlorothiazide. 3) potassium-protective diuretics, which are low-potency diuretics, such as spironolactone and aminoglutethimide. Another category is carbonic anhydrase inhibitors, of which acetazolamide is the representative.