Magnesium deficiency produces neuromuscular disorders. It may cause weakness, tremors, tetany, and convulsions. Magnesium deficiency is described with cardiac arrhythmias. The concept that magnesium deficiency may cause arrhythmias is repeatedly expressed.
Increased magnesium levels relate mostly to patients in renal failure. Marked increases may be found in such patients who take magnesium salts (eg, as antacids which contain magnesium).