Magnesium deficiency is very common. Chronic emotional and physical stresses deplete magnesium. In angina, there is a direct correlation between deficiency and frequency of chest pain. Various bowel diseases and some GI medications, such as histamine 2 antagonists, may impair absorption of dietary and supplemental magnesium. Long-term diuretic therapy, commonly prescribed to treat high blood pressure, is another problem. It drains the body of many important minerals, including magnesium. Supplementation is essential for anyone on such a program.