In the clinical setting, blood tests for electrolytes are performed: first of all, in patients with a high suspicion of hypokalemia, if there are severe clinical symptoms such as vomiting, diarrhea and profuse sweating, the possibility of hypokalemia is considered. Patients with high doses of diuretics and ascites discharge are also prone to hypokalemia. If the patient has chest tightness and the ECG examination reveals U waves and slow heart rate, this condition is mainly considered to be caused by hypokalemia in clinical practice. Patients with hyperthyroidism, which is easily complicated by periodic paralysis leading to hypokalemia, should also have electrolytes checked. Secondly, in patients with severe coma, such as diabetic ketoacidosis coma, renal failure uremic coma and respiratory failure, all may cause electrolyte disturbance in the body, and electrolyte examination should be performed.