Your doctor might use a potassium test if you show any signs that your kidneys aren’t working the way they should. They might also use it to keep track of how you’re doing if you already have a kidney disease. Your kidneys normally help take potassium out of your blood, so if there is a lot or not very much it could mean you have a kidney disease.

If your potassium levels are different to what the doctor would normally expect, this might be a sign of other conditions too.

You should tell your doctor about any medicines that you’ve been taking. Some medicines can affect the results of the test, so it’s important that your doctor knows about these.

A potassium test is just like a regular blood test. The doctor or nurse will usually take a small amount of blood from a vein in your arm using a small needle. Don’t worry - they’re really good at it!

A potassium test won’t hurt much. You might feel a tiny scratch when the needle is put in, but that’s it.

If you don’t like needles tell the person who is taking the sample so that they can help you to relax. If you feel a bit dizzy or light headed, tell the person doing the test and they will get you to lie down until you feel better.

Your blood sample will have your name put on it. Then it will be sent off to a lab where the amount of potassium in your blood is checked. When your doctor gets the results back he or she will talk to you about them and tell you what they mean.

If you have any other questions, you can ask your doctor, or chat to other people about potassium tests in the Medikidz forums and virtual world, Mediland.