Diuretics are widely used in clinical practice. Diuretics mainly act on the kidneys to reduce the reabsorption of urine by the kidneys, thus playing a diuretic role. Diuretics can be divided into strong, medium and low potency diuretics according to their mechanism of action. The strong diuretics are usually referred to as furosemide, which usually has the strongest diuretic effect. Medium-acting diuretics refer to thiazide diuretics, and the representative drug is hydrochlorothiazide. Low-potency diuretics refer to potassium-preserving diuretics, and potassium-preserving diuretics, such as spironolactone and aminoglutethimide, are commonly used. Diuretics are widely used in clinical practice, but they also have many side effects. Excessive application of diuretics can cause loss of water and electrolytes in the body, so it is necessary to pay attention to the reasonable use of drugs in clinical practice.