Magnesium is a mineral that is present in relatively large amounts in the body. The average person's body contains about 25 grams of magnesium, and about half of that is in the bones. Magnesium is important in more than 300 chemical reactions that keep the body working properly. People get magnesium from their diet, but sometimes magnesium supplements are needed if magnesium levels are too low. Magnesium is required for the proper growth and maintenance of bones. It is also required for the proper function of nerves, muscles, and many other parts of the body. It also helps neutralize stomach acid and helps move stools through the intestine.
Some people take magnesium for diseases of the heart and blood vessels including chest pain, irregular heartbeat, high blood pressure, high levels of "bad" cholesterol called low-density lipoprotein (LDL) cholesterol, low levels of "good" cholesterol called high-density lipoprotein (HDL) cholesterol, heart valve disease (mitral valve prolapse), and heart attack.
Magnesium is also used for treating attention deficit-hyperactivity disorder (ADHD), anxiety, chronic fatigue syndrome (CFS), Lyme disease, fibromyalgia, leg cramps during pregnancy, diabetes, kidney stones, migraineheadaches, weak bones (osteoporosis), premenstrual syndrome (PMS), altitude sickness, urinary incontinence, restless leg syndrome, asthma, hayfever, multiple sclerosis, and for preventing hearing loss.
Athletes sometimes use magnesium to increase energy and endurance.
Some people put magnesium on their skin to treat infected skin ulcers, boils, and carbuncles; and to speed up wound healing. Magnesium is also used as a cold compress in the treatment of a severe skin infection caused by strep bacteria (erysipelas) and as a hot compress for deep-seated skin infections.