Potassium
An electrolyte essential for heart rhythm and muscle function. Both high and low levels can affect the heart.
Typical reference range
| Range | Unit |
|---|---|
| 3.3–4.9 | mmol/l |
What Potassium measures
Potassium is an electrolyte, a charged mineral your body relies on for many everyday processes. It helps carry the electrical signals that let nerves fire and muscles contract, and it plays a central role in maintaining a steady, regular heartbeat.
Because these functions are so sensitive, the body works hard to keep potassium within a narrow range, balancing what you take in through food against what is filtered and released, mainly by the kidneys. This tight regulation is one reason potassium is such a useful marker to track over time.
On a lab report, potassium is usually measured as part of a broader metabolic panel, sitting alongside sodium and kidney markers so a clinician can read the whole electrolyte and kidney picture together rather than any single value in isolation.
What a high Potassium can mean
A high potassium result (sometimes called hyperkalemia) can be associated with several things, and the pattern usually matters more than one reading on its own.
- Reduced kidney function, since the kidneys are the main route for clearing potassium from the body.
- Certain common medications, including some blood-pressure drugs and potassium-sparing diuretics.
- Large potassium intake from diet or supplements in some situations.
An important practical point: a falsely high reading is common when red blood cells break apart during the blood draw or handling (called hemolysis). Because of this, a surprising high is often simply rechecked with a fresh sample before anything is concluded.
A markedly high potassium level can affect heart rhythm, so a notably high or symptomatic result needs prompt medical attention. Always discuss your result with a clinician who can see the full context.
What a low Potassium can mean
A low potassium result (sometimes called hypokalemia) is also read in context, and it can be associated with a range of causes.
- Fluid and electrolyte losses, such as those that follow prolonged vomiting or diarrhea.
- Diuretics and some other medications that increase potassium loss.
- Other underlying causes a clinician may explore based on your wider picture.
When potassium runs low, possible effects can include muscle weakness, cramps, and changes in heart rhythm, which is why the value is watched carefully rather than viewed as a minor detail.
Both directions matter here: a level that drifts too low deserves the same attention as one that runs high. A single number rarely tells the whole story, so it is best to discuss the result with a clinician who can interpret it alongside your symptoms, medications, and other markers.
Track your Potassium over time in Quanome — it reads your lab reports (PDF or photo) on your device, charts each marker against its range, and an AI coach explains what your trends mean alongside your Apple Health and DNA.