Magnesium, Serum Concentration
This test measures the amount of magnesium in your blood serum, an essential mineral that plays a key role in muscle and nerve function, blood pressure regulation, and bone health.
["Magnesium levels help assess your body’s mineral balance and overall health."]
Key facts at a glance
- LOINC
- 32329-5
- Short code
- Magnesium Spec-sCnc
- Synonyms
- Magnesium Spec-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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like muscle weakness, cramps, irregular heartbeat, or signs of low or high magnesium levels. It could also be part of routine check-ups, especially if you have conditions like kidney disease, diabetes, or heart problems. Some medications or dietary factors may also trigger this test.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw if it’s part of a metabolic panel. Wear comfortable clothing and plan to stay near the testing site for a short time.
How the Test Works
A healthcare professional will draw blood from a vein in your arm. The blood sample is sent to a lab, where it is analyzed to measure magnesium concentration using a specialized method (often automated chemistry or ion-selective electrode techniques).
What the Results Mean
Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). While reference ranges vary by lab, low levels may indicate conditions like malnutrition, kidney disease, or certain medications. High levels can suggest over-supplementation, kidney problems, or certain metabolic disorders.
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.
◆Associated findings1
Short name
Magnesium Level
Frequently asked questions
Low magnesium levels can affect muscle and nerve function, potentially leading to weakness, seizures, or abnormal heart rhythms. Chronic deficiency may also contribute to conditions like hypertension or diabetes. Conversely, dangerously high levels can cause nausea, confusion, or irregular heartbeats. Monitoring magnesium is important for patients with chronic illnesses or those on long-term medications.
The frequency depends on your health status. Routine adults typically don’t need this test unless recommended by their provider. If you have a condition like kidney disease, diabetes, or heart issues, your doctor may order it more often to track changes.
Yes, diet can influence magnesium levels. Foods rich in magnesium (nuts, seeds, leafy greens, whole grains) may temporarily raise your level. Avoiding excessive alcohol or certain medications (like diuretics) can help ensure accurate 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