Na
The primary extracellular electrolyte — tightly regulated by kidneys and hormones.
What is it
Sodium is the main electrolyte in extracellular fluid and is essential to fluid balance, nerve function, and blood pressure regulation.
Why it's measured
Sodium levels have been used in clinical evaluation of hydration, kidney function, and hormonal balance in research and practice.
Reference range
Standard laboratory reference
136 – 145 mEq/L
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with dehydration and certain endocrine conditions in research literature.
Lower
Has been associated with overhydration, kidney issues, and certain medications in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of standard electrolyte panels.
Related markers
Common questions
Sodium is the main electrolyte in extracellular fluid and is essential to fluid balance, nerve function, and blood pressure regulation.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Sodium is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Sodium is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.