A magnesium blood test is performed to measure magnesium levels in the blood and to monitor treatment efficacy of magnesium supplements. Magnesium is a mineral that plays an essential role in metabolism, nerve functioning, and maintenance of healthy bones. Its deficiency can cause symptoms such as muscle weakness, irregular heartbeat, and muscle twitch.
Magnesium deficiency may be a sign of malnutrition and diabetes. If your results show a higher than normal amount of magnesium, it may be a sign of dehydration and kidney disease.