Hypokalemia is a pathological state in which the serum potassium concentration is below 3.5 mmol/L. Potassium deficiency hypokalemia is characterized by a decrease in the total amount of potassium, intracellular potassium and serum potassium concentration in the body, which is essentially a potassium deficiency. 1. Insufficient intake: prolonged fasting, little food, daily potassium intake less than 3g for more than 2 weeks. 2, Excessive excretion: There are three main ways of potassium excretion, mainly through the gastrointestinal tract or kidney loss, followed by sweat. (1) Potassium loss via kidney: 85% of potassium is excreted by kidney in normal people. Ninety-eight percent of the potassium filtered by the glomerulus is reabsorbed, while the potassium excreted in the urine is mainly secreted by the distal tubule, i.e., from the K+-Na+ exchange. That is, the kidneys excrete K+ while retaining Na+. In clinical practice, prolonged use of potassium-removing diuretics or large amounts of osmotic diuretics; prolonged use of adrenocorticotropic hormones; certain adrenocortical disorders such as primary aldosteronism; secondary aldosteronism due to Conn syndrome, Batter syndrome, reninoma, renal artery stenosis, etc.; increased secretion of deoxycorticosterone due to Cushing’s syndrome, 11 or 17 hydroxylase deficiency, etc.; and certain renal diseases. Increased secretion; certain renal diseases such as renal tubular acidosis; the application of certain antibiotics, such as penicillin, gentamicin, carbenicillin, polymyxin B, etc.; various causes of alkalosis, acidosis recovery period. (2) Potassium loss from the gastrointestinal tract: digestive juices are rich in potassium, and when repeated vomiting, diarrhea or gastrointestinal drainage occurs, a large amount of potassium is lost. (3) Abnormal distribution: such as periodic paralysis, when the body is not deficient in potassium, but hypokalemia occurs due to potassium entering the cells.