Potassium Blood Test Test
A potassium blood test measures the amount of potassium in your blood. Potassium is an electrolyte that helps control fluid balance, nerve and muscle activity, and heart function. Abnormal levels can signal health issues like kidney disease or high blood pressure.
What this test measures
A potassium blood test measures the amount of potassium in your blood. Potassium is a type of electrolyte that helps control fluid levels, acid-base balance, and muscle and nerve activity.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
Too much potassium in the blood (hyperkalemia) may be caused by kidney disease, Addison disease, injuries, burns, surgery, poorly controlled type 1 diabetes, or side effects of certain medicines. A diet very high in potassium or potassium supplements can also raise levels.
Lower-than-normal results
Too little potassium in the blood (hypokalemia) may be a sign of side effects from diuretics, fluid loss from diarrhea or vomiting, heavy sweating, laxative overuse, adrenal gland disorders, kidney disease, or alcohol use disorder. A diet too low in potassium is not common.
Frequently asked questions
Why do I need a potassium blood test?
The test is often part of a routine electrolyte panel. It may be used to monitor or diagnose conditions related to abnormal potassium levels, such as kidney disease, high blood pressure, and heart disease.
What does high potassium mean?
High potassium (hyperkalemia) can be caused by kidney disease, Addison disease, injuries, burns, surgery, poorly controlled type 1 diabetes, or side effects of certain medicines. Eating very large amounts of potassium-rich foods or taking potassium supplements can also raise levels.
What does low potassium mean?
Low potassium (hypokalemia) may be a sign of diuretic side effects, fluid loss from diarrhea or vomiting, heavy sweating, laxative overuse, adrenal gland disorders, kidney disease, or alcohol use disorder.
Can medicines affect my potassium levels?
Yes, certain prescription and over-the-counter medicines and supplements may raise your potassium levels. Diuretics and antibiotics are examples of medicines that can affect potassium.
Should I avoid licorice before the test?
You should not eat natural black licorice for at least two weeks before your test because it may lower your levels. Most licorice products in the U.S. don't contain natural licorice, but check the ingredients label to be sure.
Related lab tests
Sources
- MedlinePlus: Potassium Blood Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.