The normal value of blood potassium is 3.5-5.5mmol/L. Blood potassium is an important ion to maintain the cardiovascular system and neuromuscular excitability, only when the blood potassium is within the normal range, it can maintain the normal functioning of the organism, neither too low nor too high blood potassium will do, it is very important to maintain blood potassium. If blood potassium is lower than 3.5 mmol/L, it is hypokalemia, which is commonly seen in patients with long-term poor diet and application of diuretics. Supplementation of potassium chloride extended-release tablets or potassium chloride injection is needed so that the symptoms of hypokalemia can be improved. If the blood potassium concentration is more than 5.5mmol/L, it is hyperkalemia, which is common in acidosis and other diseases, then diuretics should be applied and potassium salt intake should be restricted. If necessary, hypertonic glucose and insulin can be titrated, and sodium bicarbonate injection can also be applied to reduce blood potassium.