What is a magnesium blood test?A magnesium blood test measures the amount of magnesium in your blood. Magnesium is a type of electrolyte. Electrolytes are electrically charged minerals that are responsible for many important functions and processes in your body.Your body needs magnesium to help your muscles, nerves, and heart work properly. Magnesium also helps control blood pressure and blood sugar.Most of your body's magnesium is in your bones and cells. But a small amount is found in your blood. Magnesium levels in the blood that are too low or too high can be a sign of a serious health problem.Other names: Mg, Mag, Magnesium-Serum
