Hypomagnesemia - Diagnosis

Diagnosis

The diagnosis can be made by finding a plasma magnesium concentration of less than 0.7 mmol/l. Since most magnesium is intracellular, a body deficit can be present with a normal plasma concentration. In addition to hypomagnesemia, up to 40% cases will also have hypocalcemia while in up to 60% of cases, hypokalemia will also be present. The ECG shows a prolonged QT interval.