Patient education: Magnesium test (The Basics)

What is a magnesium test? — 

This is a type of blood test. It measures the amount of magnesium in the body.

Magnesium is one of many substances in the body called "electrolytes." Having the right amount of magnesium in the body is important for:

●Helping nerves and muscles work properly

●Bone and heart health

●Keeping blood pressure under control

●Helping the body make certain hormones

The kidneys help keep the magnesium level where it should be. Having too much or too little magnesium can be a sign of a health problem.

Why might I get a magnesium test? — 

Your doctor might want you to get a magnesium test:

●If you have symptoms of too little magnesium – These can include muscle cramps or spasms, seizures, low energy, or confusion.

●If you have symptoms of too much magnesium – These can include nausea, flushing, sleepiness, headache, muscle paralysis, and heart problems.

●If you have a health condition that can affect your magnesium level – These include diabetes, kidney disease, or alcohol use disorder. Some medicines can also affect your magnesium level.

●To check how treatment is working if you are being treated for low magnesium

How do I prepare for a magnesium test? — 

You need to get a "blood draw." Your doctor or nurse will tell you where to go for this.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing the blood to get to your arm.

What happens during a blood draw? — 

A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — 

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your magnesium test shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out the cause.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

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