Potassium is an electrolyte that helps your nerves fire, your muscles contract, and your heartbeat stay steady. Here is how to read your potassium result and what a high or low value can point to, in plain language.
Potassium is a mineral and electrolyte that your cells, nerves, and muscles need to work properly. It is especially important for a steady heartbeat. Your body keeps blood potassium in a fairly narrow range, and the kidneys do most of the work of removing any excess.
Potassium is reported in milliequivalents per litre (mEq/L), which is the same as millimoles per litre (mmol/L) for potassium. A normal range is often around 3.7 to 5.2 mEq/L, though laboratories differ. Because potassium affects the heart, values well outside the normal range are taken seriously even when you feel well.
A high level, called hyperkalemia, can relate to kidney problems, certain medicines, or how the sample was collected. A low level, called hypokalemia, can follow fluid loss, some medicines such as diuretics, or other conditions. Sometimes a high reading is a false alarm caused by red blood cells breaking during the blood draw, which is why an unexpected result may be repeated.
Upload a photo or PDF of your metabolic panel and Mednex reads your potassium and the rest of your electrolytes back to you in plain language, then tracks them over time.
Decode my labsContent last reviewed 9 July 2026. Reference ranges vary by laboratory; always read your results against the range printed on your own report.
This page explains a common lab marker in general terms using public information from the U.S. National Library of Medicine and other NIH sources. It is educational and is not a diagnosis or medical advice. Reference ranges differ between laboratories and the meaning of a result depends on your age, sex, medications, and overall health. Always discuss your own results with the clinician who ordered them.