Interpret Your Magnesium Results
Enter your Mg value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Magnesium Normal Ranges
Magnesium is the second most abundant intracellular cation and a cofactor in over 300 enzymatic reactions, including energy production (ATP synthesis), protein synthesis, DNA replication, and membrane transport.
| Age Group | Reference Range | Unit | Notes |
|---|---|---|---|
| Adults (18–64) | 1.7 – 2.2 | mg/dL | — |
Also reported in: mmol/L.
Critical (Panic) Values
Critical Low: < 1 mg/dL. Critical High: > 4.9 mg/dL. Values outside these limits require immediate clinical attention.
Why Doctors Order the Magnesium Test
Hypomagnesemia is remarkably common in hospitalized patients (up to 65%) and is frequently overlooked. It is closely linked to hypokalemia — magnesium deficiency impairs renal potassium retention, making hypokalemia refractory to potassium replacement until magnesium is corrected.
How to Enter Your Mg Result
Magnesium can be reported in mg/dL or mmol/L. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
What a Low or High Mg Can Be Associated With
Below the reference range
- Chronic diarrhea and malabsorption (most common GI cause)
- Proton pump inhibitors (PPIs) — can cause renal magnesium wasting with long-term use
- Diuretics (loop and thiazide — increase renal magnesium excretion)
- Alcohol excess (increased renal losses and poor intake)
- Type 2 diabetes with poor control (osmotic diuresis)
Above the reference range
- Renal failure (most common — reduced excretion)
- Excessive magnesium supplementation or antacid use
- Intravenous magnesium therapy (pre-eclampsia treatment)
- Hypothyroidism and adrenal insufficiency
This interpreter flags a result at or below 1 mg/dL or at or above 4.9 mg/dL as a critical value. Results that extreme are uncommon — contact your doctor promptly, and seek urgent medical care if you feel unwell.
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your Mg Result
Before you read too much into a result, consider whether any of these applied:
- Hemolysis (magnesium is intracellular — hemolysis falsely elevates serum magnesium)
- Prolonged tourniquet use
- Antacids and laxatives containing magnesium
- Renal function (kidney disease markedly affects serum magnesium)
Preparing for the test: No special preparation. Serum magnesium should ideally be drawn in the morning fasting.
Symptoms That Often Prompt Mg Testing
- Muscle cramps and tremors
- Weakness and fatigue
- Cardiac arrhythmias (especially torsades de pointes)
- Nystagmus and ataxia (in severe deficiency)
- Seizures (severe hypomagnesemia)
Want the full clinical guide to Magnesium?
Reference ranges, causes, symptoms, preparation, and FAQs.