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Metabolic Health

Sodium Test

A key electrolyte that controls fluid balance, blood pressure, and nerve and muscle function.

Physician reviewed
Results in 1–3 days
4,000+ lab locations

What is Sodium?

A key electrolyte that controls fluid balance, blood pressure, and nerve and muscle function.

Sodium Reference Range

These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.

PopulationRange
age 18+135 – 145 mmol/L

Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.

What your Sodium result may mean

Higher than range

Often reflects dehydration or excess salt intake.

Lower than range

Can reflect overhydration, certain medications (especially diuretics), or hormonal conditions.

Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.

Related Metabolic Health biomarkers

Markers commonly tested alongside Sodium.

Frequently asked

No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.

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