Potassium is an important element needed by the body. Potassium regulates the proper osmotic pressure in cells and the acid-base balance of body fluids, and participates in the metabolism of sugars and proteins in cells. It helps maintain healthy nerves and a normal heartbeat pattern, can prevent strokes, and assists in normal muscle contraction. This shows the importance of potassium to the human body, but it can be equally dangerous to health if the blood potassium in the body is elevated. Serum potassium ion >5 mEq/L is called hyperkalemia, 6-7 mEq/L is moderate hyperkalemia, and >7 mEq/L is severe hyperkalemia. The most common cause of hyperkalemia is renal failure. Its symptomatic manifestations depend mainly on the primary disease, the degree and speed of elevated blood potassium, etc. Patients generally have no specific symptoms, mainly the toxic effect of potassium on the myocardium and bone iliac muscle. I. Elevated blood potassium inhibits myocardial contraction, resulting in slow heart rhythm, arrhythmia and, in severe cases, ventricular fibrillation and cardiac arrest in diastole. Second, elevated blood potassium manifests itself in neuromuscular symptoms. Early on, there is often numbness of the extremities and perioral sensation, extreme fatigue, muscle aches, pale limbs, and wet and cold. When the blood potassium concentration reaches 7 mmol/L, the limbs become numb and limp, first for the trunk, then for the limbs, and finally affecting the whistling muscles and asphyxia occurs. Third, when the blood potassium is high, it can also cause metabolic acidosis in human body. The main causes of elevated blood potassium are: i. Excessive intake of potassium, like inputting potassium-containing solutions too fast or too much, inputting blood that has been stored for too long or using a large amount of penicillin potassium salt, can cause excessive blood potassium. Second, reduced renal potassium excretion, which is mostly seen in the oliguric and anuric phases of renal failure, hyperalgesia, etc. Third, intracellular potassium migration, commonly caused by the input of incompatible blood or other causes of severe hemolysis, hypoxia, acidosis and trauma-induced extrusion syndrome, etc. IV. Decrease in extracellular fluid volume, which is mostly seen in hemoconcentration due to dehydration, blood loss or shock. To avoid the damage caused by elevated blood potassium to the body is the need to avoid its triggering factors.