Magnesium Test-Why am I having this test?

Magnesium test is done to determine how much magnesium you have in your blood. You may have this test if you:

• Are a pregnant woman and you have signs of high blood pressure (preeclampsia).
• Have diabetes (diabetes mellitus).
• Have a history of alcohol abuse.
• Have recently had surgery and are unable to eat normally.
• Have a disorder of the thyroid or parathyroid gland.
• Use antacid medicines frequently.
• Have long-term (chronic) kidney disease.
• Have levels of potassium and calcium that are regularly (chronically) low.
• Lack certain nutrients in your diet (malnourishment).

What is being tested?

This test measures the amount of magnesium in your blood. Magnesium is a mineral that helps with many processes in the body, including nerve and heart function. It helps regulate your heartbeat and blood pressure.

Your potassium and calcium levels may also be tested because blood magnesium levels are closely related to the levels of these other minerals.

What kind of sample is taken?

A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.

How are the results reported?

Your test results will be reported as a value that indicates how much magnesium is in your blood. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common normal reference ranges are:

• Adult: 1.3–2.1 mEq/L or 0.65–1.05 mmol/L (SI units).
• Child: 1.4–1.7 mEq/L.
• Newborn: 1.4–2 mEq/L.

What do the results mean?

Results that are higher than your reference range mean that you have too much magnesium in your blood, which may result from:

• Poor kidney function (renal insufficiency).
• Addison’s disease, also called primary adrenal insufficiency.
• Excess use of antacid medicines.
• The thyroid gland not producing enough thyroid hormone (hypothyroidism).

Results that are lower than your reference range mean that you have too little magnesium in your blood, which may result from:

• Not eating enough nutrients (malnutrition).
• Your intestines not absorbing nutrients normally.
• The parathyroid glands not producing enough hormones (hypoparathyroidism).
• Alcohol abuse.
• Chronic kidney disease.
• Poorly-controlled diabetes (diabetic ketoacidosis).

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

Ask your health care provider, or the department that is doing the test:

• When will my results be ready?
• How will I get my results?
• What are my treatment options?
• What other tests do I need?
• What are my next steps?

Summary

• A magnesium test is done to determine how much magnesium you have in your blood.
• Your potassium and calcium levels may also be tested because blood magnesium levels are closely related to the levels of these other minerals.
• Talk with your health care provider about what your results mean. Certain medical conditions can cause high or low magnesium levels.