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Serum Magnesium Concentration (Mass Concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of magnesium in your blood serum, an important mineral that helps with muscle and nerve function, bone health, and many other body processes.

Quick summary

["Magnesium levels help ensure your body’s vital functions stay balanced."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
22422-0
Short code
M gallisep Ab Ser Ql
Synonyms
M gallisep Ab Ser Ql
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for low or high magnesium levels, which can occur due to conditions like kidney problems, certain medications, or dietary deficiencies. It’s also used to monitor magnesium levels during treatments like chemotherapy or if you have symptoms like muscle weakness, cramps, or irregular heartbeat.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw if your test is part of a broader metabolic panel. Bring any medications or supplements you’re taking, as they can affect results.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood sample is then sent to a lab for analysis.

What Are Possible Results?

Results are typically reported in milligrams per deciliter (mg/dL). Low magnesium levels (hypomagnesemia) or high levels (hypermagnesium) may indicate underlying health concerns that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Magnesium

Frequently asked questions

What Are Common Causes of Abnormal Results?
Low magnesium levels can be caused by poor diet, kidney disease, vomiting, diarrhea, or certain medications like diuretics or antibiotics. High magnesium levels may result from kidney failure, excessive magnesium intake (e.g., from supplements), or certain medical conditions like Addison’s disease.
How Does This Test Relate to My Overall Health?
Magnesium is crucial for nerve and muscle function, blood pressure regulation, and energy production. Abnormal levels can lead to symptoms like muscle spasms, fatigue, or heart rhythm issues. Regular monitoring helps manage conditions like diabetes, heart disease, or electrolyte imbalances.
Can I Avoid This Test?
No, this test is often part of routine or condition-specific evaluations. If your provider recommends it, it’s important to follow through to ensure your health is properly monitored.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy