What causes hypokalemia? Low blood potassium typically occurs because of an excessive loss of potassium in your digestive tract. This may be due to frequent vomiting, diarrhea or laxative use. Other causes of hypokalemia include: Eating disorders, such as bulimia nervosa. Excessive sweating (hyperhidrosis). Alcohol use disorder. Water pills (diuretics). Diuretics can cause too much potassium to be expelled through your pee (urine). Other medications such as insulin, certain antibiotics and corticosteroids. Adrenal disorders, such as primary aldosteronism and Cushing’s syndrome. Chronic kidney disease. Low magnesium levels (hypomagnesemia). Certain kidney conditions, such as Bartter’s syndrome and Gitelman syndrome. Both are rare genetic kidney disorders that cause imbalances in your body.