Oral potassium chloride is fast-acting and takes effect after 2-4 hours. The normal value of blood potassium is 3.5-5.5 mmol/L. When the blood potassium concentration is lower than 3.5 mmol/L it is called hypokalemia. When the plasma concentration is less than 2.5 mmol/L, it is already classified as severe hypokalemia. Hyperkalemia affects the excitability of nerves and muscles, as well as the excitability of the heart, and requires aggressive treatment. The treatment of hyperkalemia can be intravenous potassium supplementation or oral potassium supplementation. The principle of intravenous potassium supplementation is that the speed is not too fast and the concentration is not too high, so intravenous potassium supplementation has the problems of slow potassium supplementation and small potassium dose. Oral potassium chloride includes oral potassium chloride extended-release tablets and potassium chloride injection. Compared with intravenous potassium supplementation, the advantages of oral potassium supplementation are as follows: 1. It is not affected by the speed of potassium supplementation and the concentration of potassium supplementation, so as long as the gastrointestinal tract of the patient can tolerate it, potassium supplementation can be performed as soon as possible, and hypokalemia can be corrected as soon as possible. 2. Oral potassium chloride injection is absorbed faster than potassium chloride extended-release tablets, and the patient will consciously feel better about his/her symptoms after 2 hours, and the blood potassium will rise significantly after 4-6 hours. 3. After 4-6 hours, the blood potassium will rise significantly.3. Oral potassium supplementation, as long as the renal function is normal there will be no serious hyperkalemia.