Magnesium, Serum Concentration
This test measures the amount of magnesium in your blood serum, a mineral essential for muscle and nerve function, blood clotting, and bone health.
["Magnesium levels help assess potential deficiencies or excesses that may affect your health."]
Key facts at a glance
- LOINC
- 52911-5
- Short code
- Magnesium Tiss-sCnt
- Synonyms
- Magnesium Tiss-sCnt
- 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 a serum magnesium test to check for low or high levels, which can occur due to conditions like kidney problems, certain medications, or chronic health issues. It may also be used to monitor treatment responses or diagnose symptoms like muscle weakness, cramps, or irregular heart rhythms.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader metabolic panel. Bring any medications you’re currently taking to your appointment.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and typically painless. The blood sample is sent to a lab for analysis.
What Are Normal Results?
Results are not provided with specific numeric ranges here, as they can vary by lab and testing methods. Your doctor will interpret the results in relation to your overall health and symptoms.
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.
Low magnesium levels (hypomagnesemia) can cause muscle spasms, tremors, irregular heartbeat, or seizures. High magnesium levels (hypermagnesia) may lead to nausea, weakness, or slowed heart rate. Chronic imbalances can affect multiple body systems, so your doctor will consider your medical history and other test results when evaluating results.
Short name
Serum Magnesium
Frequently asked questions
How long does it take to get my results?
Can I eat or drink before this test?
What should I do if I have concerns about my magnesium levels?
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