An analysis of hypermagnesemia and hypomagnesemia.

Serum magnesium (Mg) was measured in 6,252 patients; in 1,246 (19.9%) the value was abnormal. Hypermagnesemia (serum Mg greater than or equal to 3.9 mg/dl) was observed in 51 patients (0.8%) and hypomagnesemia (Mg less than or equal to 1.5 mg/dl) in 165 (2.6%). Hypermagnesemia was found in patients with renal failure treated with Mg-containing antacids or cathartics, or with eclamptic convulsions treated with Mg sulfate. The most frequent clinical finding of hypermagnesemia was urinary disturbance, although various other neurological signs and symptoms were observed. Hypomagnesemia was seen in patients with various diseases such as cancer, hepatic cirrhosis, cerebrovascular disease, and generally poor condition. Abnormalities of electrolytes other than Mg were also frequently observed. The most common clinical findings of hypomagnesemia were personality changes and depression. The differentiation from psychiatric disease is important.