When the serum potassium concentration is greater than 5.5 mmol/L it is called hyperkalemia. The main threat of hyperkalemia to the organism is cardiac depression, which is mainly manifested by decreased myocardial contractile function, muffled heart sounds, which can lead to cardiac arrest, heart rate slowing, ventricular pre-systole, atrioventricular block, ventricular fibrillation, etc., and ischemia-like conditions such as early increase and late decrease in blood pressure and vasoconstriction. The primary cause should be recognized early and treated aggressively to control potassium intake with sodium lactate or bicarbonate solutions, calcium, hypertonic saline, glucose, and insulin, as well as selective β2 agonists such as salbutamol; potassium excretion should also be facilitated, with the use of diuretics as well as cation-exchange resins or dialysis therapy.