Magnesium, Serum Concentration
This test measures the amount of magnesium, a mineral essential for many bodily functions, in your blood serum. Low or high levels may indicate underlying health concerns.
["Magnesium levels help assess electrolyte balance and overall health."]
Key facts at a glance
- LOINC
- 109594-2
- Short code
- Magnesium Msmt Bld
- Synonyms
- Magnesium Msmt Bld
- Category
- electrolyte
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 1.7
- Ref high
- 2.2
- Critical range
- 1 N/A – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83735
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to check for conditions like hypomagnesemia (low magnesium) or hypermagnesemia (high magnesium), which can affect muscle function, nerve signals, or heart rhythm. It may also be used in monitoring certain medications or medical conditions, such as kidney disease or heart problems.
What to Expect Before the Test
No special preparation is typically needed, but you may be asked to fast for a few hours before the blood draw if your provider specifies. Avoid consuming magnesium-rich foods (like nuts, leafy greens, or supplements) for 24 hours prior if instructed.
What Happens During the Test?
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the procedure is quick and usually painless. The blood sample is sent to a lab for analysis.
What Does the Test Result Mean?
Results are compared to standard reference ranges, but exact values can vary by lab. Low magnesium levels may cause symptoms like muscle cramps, weakness, or irregular heartbeat, while high levels can lead to nausea, muscle weakness, or confusion. Your provider will interpret results in the context of your overall health.
Reference range
Adult: 1.7-2.2 mg/dLN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal magnesium levels can impact nerve and muscle function, heart rhythm, and bone health. Low magnesium is often associated with conditions like malnutrition, kidney disease, or certain medications, while high levels may result from overuse of magnesium supplements or kidney problems. Regular monitoring is important for patients with chronic conditions or those taking medications that affect magnesium balance.
Short name
Magnesium Level
Frequently asked questions
What causes low magnesium levels?
What are the symptoms of abnormal magnesium levels?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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