Serum Magnesium Concentration
This test measures the amount of magnesium, a mineral essential for many bodily functions, in your blood serum.
["Magnesium helps with muscle and nerve function, bone health, and energy production."]
Key facts at a glance
- LOINC
- 2601-3
- Short code
- Magnesium SerPl-sCnc
- Synonyms
- Magnesium SerPl-sCnc
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 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 doctor may order this test to check for low or high magnesium levels, which can cause symptoms like muscle weakness, cramps, irregular heartbeat, or fatigue. It may also be used to monitor conditions like kidney disease, heart problems, or certain medications that affect magnesium.
What to Expect Before the Test
You can eat and drink normally before the test. No special preparation is needed, but inform your doctor about any medications you’re taking, as some (like certain antibiotics or diuretics) can affect magnesium levels.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. 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 Common Results?
Results are typically reported as a concentration in milligrams per deciliter (mg/dL). Your doctor will compare your result to your individual reference range, which may vary slightly depending on your lab and health status.
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.
Magnesium plays a critical role in muscle and nerve function, blood pressure regulation, and preventing certain heart rhythms. Low magnesium can lead to muscle spasms, weakness, or irregular heartbeat, while high levels may cause nausea, confusion, or abnormal heart rhythms. Monitoring magnesium levels helps manage conditions like kidney disease, diabetes, or electrolyte imbalances.
Short name
Magnesium Level
Frequently asked questions
What causes low magnesium levels?
What causes high magnesium levels?
How long does it take to get results?
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