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, and when the blood potassium is higher than 5.5 mmol/L, it is hyperkalemia. Under normal circumstances, the body is in a state of dynamic equilibrium with regard to the intake and excretion of potassium through diet, which can maintain the normalization of serum potassium. Potassium is an important ion to maintain the normal electrophysiology of lineage cells, and either too high or too low blood potassium will affect muscle activity. Hyperkalemia can occur when there is insufficient intake or excessive potassium excretion from the gastrointestinal and urinary tracts or when there is a shift of potassium to the intracellular level, resulting in muscle weakness, episodes of flaccid paralysis, and in severe cases, hypokalemic paralysis or even cardiac arrest. Hyperkalemia occurs mostly in patients with renal insufficiency and may also trigger cardiac arrest. Therefore, too much or too little potassium can affect the patient’s life and needs to be treated actively.