Hypokalemia is produced by the following three reasons: First, too little intake, due to the patient’s disease leads to too little potassium intake, such as eating less people, have chronic tumor consumptive disease, intestinal obstruction or even cerebral hemorrhage coma of the patient. Second, the increase of discharge, diarrhea, vomiting, gastrointestinal drainage, the application of potassium diuretics, large burns, pleural effusion or abdominal fluid volume, a lot of drainage later. Third, the transfer of potassium to the cell, like insulin plus sugar water, and alkalosis, can cause hypokalemia, and there are also diseases that can manifest as hypokalemia, like hyperthyroidism, primary aldosteronism and so on.