Is my Sodium normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal Sodium level?
Sodium is the primary extracellular electrolyte, essential for fluid balance, nerve transmission, and muscle contraction. Normal range is 136-145 mEq/L. Low sodium (hyponatremia) is the most common electrolyte disorder in hospitalized patients. High sodium (hypernatremia) usually indicates dehydration. Even mild sodium abnormalities can cause significant symptoms.
| Range | Values |
|---|---|
| Standard Reference | 136–145 mEq/L |
| High Risk | > 150 mEq/L |
| Low Risk | < 130 mEq/L |
What causes abnormal Sodium levels?
Low sodium: SIADH, diuretics (thiazides), heart failure, cirrhosis, nephrotic syndrome, adrenal insufficiency, hypothyroidism, excessive water intake, and endurance exercise. High sodium: dehydration (most common), diabetes insipidus (central or nephrogenic), osmotic diuresis (diabetic ketoacidosis), excessive sodium intake, and reduced water access (elderly, hospitalized patients).
When should you see a doctor?
See your doctor if sodium is below 130 mEq/L or above 150 mEq/L. Severe hyponatremia (below 120 mEq/L) is a medical emergency — rapid correction must be avoided (risk of osmotic demyelination syndrome). Symptoms of hyponatremia include confusion, nausea, seizures, and coma.
Sodium and longevity
Chronic mild hyponatremia (130-135 mEq/L) is remarkably common in older adults and significantly increases fall risk by causing subtle gait instability and cognitive impairment. Falls are a leading cause of morbidity and mortality in the elderly. Thiazide diuretics, a common blood pressure medication, are the most frequent iatrogenic cause. Regular monitoring and medication review are important preventive measures in aging populations.
Where to get a Sodium test
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Related biomarkers
These biomarkers are often tested alongside Sodium for a more complete picture.
Frequently asked questions
What is a normal sodium level?
What causes low sodium?
Can drinking too much water lower sodium?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.