Kidney system

Potassium

K

A critical intracellular electrolyte essential to heart and muscle function.

What is it

Potassium — in plain English.

Potassium is the primary intracellular electrolyte and is essential to heart rhythm, muscle function, and nerve signaling. Levels are tightly regulated.

Why it's measured

What K can reveal.

Potassium imbalance has clinical significance in cardiac and neuromuscular function in published research.

Reference range

Where most laboratories draw the standard line.

Standard laboratory reference

3.5 – 5.0 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

Higher vs. lower K — at a high level.

Elevated

Has been associated with kidney dysfunction and certain medications in research literature; can affect heart rhythm.

Lower

Has been associated with diuretic use and GI losses in research literature; can affect heart rhythm.

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 K is typically run.

Part of standard electrolyte panels.

Related markers

Often measured alongside K.

Measured in

K 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
Back to all biomarkers

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.