Magnesium, Serum 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, blood pressure, and bone health."]
Key facts at a glance
- LOINC
- 26708-8
- Short code
- Magnesium Stl-sCnt
- Synonyms
- Magnesium Stl-sCnt
- Category
- electrolyte
- Sample
- stool
- Container
- Clean container
- 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 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
Why Might You Need This Test?
Your doctor may order this test to check for low or high magnesium levels, which can affect how your body uses calcium, potassium, and other minerals. It may also be done if you have symptoms like muscle twitches, cramps, irregular heartbeat, or fatigue, or if you have conditions like kidney disease, vomiting, or certain medications that affect magnesium levels.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for a few hours before the test, but this depends on your doctor’s instructions. Bring any medications you’re taking to your appointment.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort. The blood sample is then sent to a lab for testing.
What Are the Possible Results?
Results will be compared to standard reference ranges for magnesium levels. Low levels (hypomagnesemia) or high levels (hypermagnesemia) may indicate underlying health concerns that need further evaluation.
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 is crucial for nerve and muscle function, blood pressure regulation, and bone health. Abnormal levels can lead to serious health issues, such as muscle spasms, irregular heartbeat, or weakened bones. Your doctor may recommend this test if you have symptoms of magnesium deficiency or if you’re taking medications that can affect magnesium levels, such as certain diuretics or antibiotics.
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