Magnesium (Mg) Test
Test Overview
A magnesium test checks the level of magnesium in the blood. Magnesium is an important electrolyte, Opens dialog needed for proper muscle, nerve, and enzyme, Opens dialog function. It also helps the body use energy and is needed to move other electrolytes (potassium and sodium) into and out of cells.
Most of the magnesium in the body is found in the bones and inside the cells. Only a tiny amount of magnesium is normally present in the blood.
Tests for other electrolytes, such as calcium, potassium, sodium, and phosphorus, may be done along with a test for magnesium.
A test for magnesium is done to:
- Find a cause for nerve and muscle problems, such as muscle twitches, irritability, and muscle weakness.
- Find the cause of symptoms such as low blood pressure, nausea, vomiting, diarrhea, dizziness, muscle weakness, and slurred speech.
- Monitor kidney function.
- Find the cause of heart problems or trouble breathing, especially in people who have kidney disease.
- Find the cause of a low calcium or potassium level that is not improving with treatment.
- Look for changes in magnesium levels caused by medicines, such as diuretics, Opens dialog.
- See if people who have heart problems need extra magnesium. Low magnesium levels can increase the chances of life-threatening heart rhythm problems.
- Measure levels when magnesium is being given for medical treatment.
A health professional uses a needle to take a blood sample, usually from the arm.
How long the test takes
The test will take a few minutes.
Watch
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
Many conditions can change magnesium levels. Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health.
Current as of: April 30, 2024
Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Current as of: April 30, 2024
Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.