Magnesium Test

About this test

This test measures the level of magnesium in your blood. Magnesium is an essential mineral — the fourth most abundant in the body — involved in over 300 biochemical reactions including energy production, protein synthesis, muscle contraction and relaxation, nerve signal transmission, heart rhythm regulation, and blood sugar control.

Low magnesium (hypomagnesemia) is one of the most common nutrient deficiencies and is frequently missed because symptoms are nonspecific. Blood magnesium also doesn't perfectly reflect total body stores — most magnesium is inside cells and bones — so even borderline-low results should be taken seriously if symptoms are present.

Components

• Magnesium (serum): Reflects the circulating magnesium in your bloodstream. Low levels commonly cause muscle cramps and twitching, headaches, difficulty sleeping, anxiety, irregular heartbeat, and fatigue. Causes include inadequate dietary intake, excessive alcohol, high-sugar diets, certain medications (diuretics, proton pump inhibitors, some antibiotics), chronic stress, and conditions like diabetes or Crohn's disease. High magnesium is less common but can occur with kidney failure or excessive supplementation.

Who is this test for?

Magnesium testing is most useful for people experiencing symptoms that may reflect low magnesium — including muscle cramps or spasms, fatigue, anxiety, irregular heartbeat, or poor sleep. It is also recommended for people with type 2 diabetes (magnesium deficiency is common), those taking diuretics or proton pump inhibitors (which deplete magnesium), and individuals who drink alcohol heavily. Magnesium is frequently low despite a normal diet because it is easily depleted.