Renal losses	Gastrointestinal losses	Intracellular shifts	Inadequate intake
Medical condition Mineralocorticoid excess Types 1 and 2 renal tubular acidosis Hypomagnesemia Intrinsic renal transport defects:  Bartter syndrome  Gitelman syndrome  Fanconi syndrome  Liddle syndrome	Chronic diarrhea Acute diarrhea Bowel preparation for colonoscopy Vomiting	Refeeding syndrome Alkalosis Thyrotoxicosis Familial periodic paralysis Hypothermia	Anorexia Starvation Total parenteral nutrition
Medications Thiazide diuretics Loop diuretics Mineralocorticoids Exogenous corticosteroids Drugs that cause magnesium depletion:  Amphotericin B  Cisplatin  Foscarnet  Aminoglycosides	Laxatives/enemas Sodium polystyrene sulfonate	Insulin Beta agonists (e.g., epinephrine, bronchodilators) Caffeine Theophylline	—