Interpret Your Sodium Results
Enter your Na 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 →
Sodium Normal Ranges
Sodium is the primary extracellular cation and the main determinant of blood osmolality (tonicity).
| Reference Range | Unit | Notes |
|---|---|---|
| 136 – 145 | mEq/L | — |
Also reported in: mmol/L.
Critical (Panic) Values
Critical Low: < 120 mEq/L. Critical High: > 160 mEq/L. Values outside these limits require immediate clinical attention.
Why Doctors Order the Sodium Test
Sodium disorders are the most common electrolyte abnormalities in hospitalized patients. Hyponatremia (low sodium) is the most frequent electrolyte disorder and a leading cause of hospital mortality if corrected too rapidly (causing osmotic demyelination syndrome/central pontine myelinolysis).
How to Enter Your Na Result
Sodium can be reported in mEq/L 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 Na Can Be Associated With
Below the reference range
- SIADH (syndrome of inappropriate ADH secretion) — most common in hospital
- Heart failure (dilutional hyponatremia)
- Liver cirrhosis (dilutional hyponatremia)
- Hypothyroidism and adrenal insufficiency
- Diuretics (especially thiazides)
Above the reference range
- Dehydration (insufficient water intake, especially in elderly)
- Diabetes insipidus (central or nephrogenic — ADH deficiency or resistance)
- Excessive sweating without water replacement
- Hyperaldosteronism
- Hypertonic saline or sodium bicarbonate administration
This interpreter flags a result at or below 120 mEq/L or at or above 160 mEq/L 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 Na Result
Before you read too much into a result, consider whether any of these applied:
- Pseudohyponatremia: falsely low sodium in severe hyperlipidemia or hyperproteinemia with older analyzers (not a problem with modern ion-selective electrode methods)
- Hyperglycemia: each 100 mg/dL rise in glucose above normal lowers measured sodium by ~1.6 mEq/L (transcellular water shift)
- Sample hemolysis: high intracellular potassium released but minimal sodium effect
Preparing for the test: No special preparation. Drawn as part of a basic or comprehensive metabolic panel (BMP/CMP).
Symptoms That Often Prompt Na Testing
- Headache
- Nausea and vomiting
- Confusion and altered mental status
- Seizures (when sodium drops rapidly below 120 mEq/L)
- Coma
Want the full clinical guide to Sodium?
Reference ranges, causes, symptoms, preparation, and FAQs.