Diuretics have different side effects depending on the site of action and mechanism of action. Diuretics can be categorized into carbonic anhydrase inhibitors, osmotic diuretics, tabular diuretics, thiazide diuretics, potassium-preserving diuretics, proteins, and peptides depending on their site of action and mechanism of action. The side effects of various diuretics are different, mainly including: decreased blood volume, electrolyte disorders, acid-base balance disorders, hyperuricemia, ototoxicity, renal stones and renal calcium deposits, decreased glucose tolerance, elevated triglycerides, and so on. Prolonged application of tabular diuretics can lead to electrolyte disturbances, most commonly hypokalemia, hyponatremia, hypocalcemia, and hypochloremic alkalosis. Hypokalemia can lead to muscle weakness in the extremities, abdominal distension, and can induce symptoms such as cardiac arrhythmias. Hyponatremia can cause symptoms such as dizziness, weakness, nausea, vomiting, and confusion. Hypocalcemia can lead to diuretic osteoporosis and induce fractures. Long-term use of diuretics can lead to abnormalities in fat metabolism and sugar metabolism in the body, which can lead to elevated blood lipids and glucose in the body, especially in patients with diabetes, long-term use of diuretics can aggravate the elevation of blood glucose. Long-term use of diuretics will aggravate kidney disease, which will lead to damage of renal tubules, and seriously induce hyperuricemia and renal insufficiency. Therefore, the use of diuretics should be carried out under a physician or pharmacist to avoid the adverse consequences of self-medication.