The causes of hypokalemia should be investigated: 1. digestive system causes, including gastrointestinal disorders such as poor absorption or diarrhea. 2. Medical origin, such as overuse of diuretics or diuretic-containing antihypertensive drugs that allow the patient to restrict the diet too much, especially meat. 3, special cases associated with hypertension, such as primary aldosteronism, which is a disease of potassium excretion and sodium retention leading to high blood pressure and low blood potassium; low blood potassium can also occur in renal artery stenosis and hyperthyroidism.