Serum or plasma mass concentration of magnesium
This test measures the amount of magnesium, a mineral essential for many bodily functions, in your blood.
["Magnesium helps with muscle and nerve function and supports energy production."]
Key facts at a glance
- LOINC
- 17323-7
- Short code
- N men Ag Ur Ql
- Synonyms
- N men Ag Ur Ql
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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 healthcare provider may order this test to check for low or high magnesium levels, which can affect muscle weakness, heart rhythm, or other health issues. It might also be done if you have conditions like kidney disease, vomiting, diarrhea, or certain medications that can affect magnesium balance.
What to Expect Before the Test
You can eat and drink normally before the test. Most often, blood is drawn from a vein in your arm. If you’re nervous, let your healthcare provider know—they can help you relax.
What to Expect During the Test
The test involves a small needle inserted into your arm to draw blood. It usually takes a few minutes, and you may feel a slight pinch. The blood is then sent to a lab for analysis.
What the Results Mean
Results help determine if your magnesium levels are too low (hypomagnesemia) or too high (hypermagnesemia). These imbalances can cause symptoms like muscle spasms, irregular heartbeat, or confusion. Your provider will discuss findings with you based on your health history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Magnesium is critical for nerve and muscle function, blood pressure regulation, and energy metabolism. Low levels may lead to weakness, seizures, or heart problems, while high levels can cause nausea, low blood pressure, or slowed breathing. This test helps diagnose or monitor conditions like electrolyte imbalances, kidney disease, or certain medications’ side effects.
Short name
Magnesium Level
Frequently asked questions
How long does it take to get my results?
What causes low magnesium levels?
What are the most common symptoms of 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