Individual test · Labcorp 080283

Magnesium, RBC

This test measures the amount of magnesium found inside your red blood cells rather than in the liquid part of your blood. It helps show whether your body has enough stored magnesium, which is useful because standard blood tests can sometimes appear normal even when your total levels are low. This measurement helps doctors determine if symptoms like muscle weakness, cramps, or fatigue are caused by a lack of magnesium. However, it does not identify the specific cause of the deficiency or diagnose underlying medical conditions on its own.