Serum or plasma concentration of magnesium
This test measures the amount of magnesium, a mineral essential for many bodily functions, in your blood.
["Magnesium levels help assess electrolyte balance and potential deficiencies or excesses."]
Key facts at a glance
- LOINC
- 44598-1
- Short code
- M-IgG Ur Ql IFE
- Synonyms
- M-IgG Ur Ql IFE
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immunofixation
- CPT
- 82784
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- 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 affect muscle function, nerve signals, or heart rhythm. It’s often done if you have symptoms like muscle cramps, weakness, irregular heartbeat, or conditions like kidney disease or diabetes.
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 electrolyte panel, 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 slight pinch, but the process is quick. The blood sample is sent to a lab for analysis.
What the Results Mean
Results help determine if your magnesium levels are within a healthy range. Low levels may indicate conditions like malnutrition, kidney problems, or certain medications. High levels could suggest overuse of supplements or certain medical treatments.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Magnesium is vital for muscle and nerve function, blood pressure regulation, and energy production. Abnormal levels can cause serious health issues, including heart rhythm disturbances, muscle spasms, or even seizures. Regular monitoring is important for people with chronic conditions like kidney disease or heart problems.
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 symptoms might indicate a magnesium imbalance?
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