Kidney system

Osmolality (calculated)

Osmolality

A calculated measure of blood solute concentration.

What is it

Osmolality (calculated) — in plain English.

Serum osmolality reflects the concentration of solutes in blood. It is calculated from sodium, glucose, and BUN, or measured directly.

Why it's measured

What Osmolality can reveal.

Osmolality has been used in evaluating hydration and certain electrolyte disorders in research literature.

Reference range

Where most laboratories draw the standard line.

Standard laboratory reference

275 – 295 mOsm/kg

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

Higher vs. lower Osmolality — at a high level.

Elevated

Has been associated with dehydration and certain endocrine conditions in research literature.

Lower

Has been associated with overhydration and certain hormonal conditions 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

When Osmolality is typically run.

Calculated when sodium, glucose, and BUN are measured.

Related markers

Often measured alongside Osmolality.

Measured in

Osmolality is one of 160 biomarkers in the Apex Panel.

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
160 biomarkers13 body systemsPhysician-reviewed
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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.