Print this article
Share this page:
Also known as: K
Formal name: Potassium

At a Glance

Why Get Tested?

To diagnose levels of potassium that are too high (hyperkalaemia) or too low (hypokalaemia)

When to Get Tested?

As part of a routine medical examination or to investigate a serious illness, such as high blood pressure or kidney disease

Sample Required?

A blood sample drawn from a vein in the arm

Test Preparation Needed?


The Test Sample

What is being tested?

Potassium is present in all body fluids, but most potassium is within your cells, with only a very small amount in the serum or plasma component of the blood. Because the blood concentration of potassium is so small, minor changes have significant consequences. If potassium goes too low or too high, your health may be impaired: you could be at risk of developing shock, respiratory failure, or heart rhythm disturbances. An abnormal concentration can alter the function of the nerves and muscles; for example, the heart muscle may lose its ability to contract.

How is the sample collected for testing?

A blood sample is taken by needle from a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

Ask a Laboratory Scientist

* indicates a required field!

Please indicate whether you are a:   

You must provide a valid email address in order to receive a response.

| |

Article Sources

« Return to Related Pages

NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.