Skip to main navigation Skip to main content Skip to footer For Medicare For Providers For Brokers For Employers Español For Individuals & Families: For Individuals & Families
Shop for Plans

Shop for Plans
Shop for your own coverage
Medical Dental Other Supplemental
Plans through your employer

Learn about the medical, dental, pharmacy, behavioral, and voluntary benefits your employer may offer.

Explore coverage through work
Learn
How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics
Looking for Medicare coverage?
Shop for Medicare plans
Member Guide
Find a Doctor
Medical Dental Other Supplemental Explore coverage through work How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics Shop for Medicare plans Member Guide Find a Doctor Log in to myCigna
Home Knowledge Center Wellness Library Potassium (K) in Blood Test

Potassium (K) in Blood Test

Test Overview

A potassium test checks how much potassium is in the blood. Potassium is both an electrolyte and a mineral. It helps keep the water (the amount of fluid inside and outside the body's cells) and electrolyte balance of the body. Potassium is also important in how nerves and muscles work.

Potassium levels often change with sodium levels. When sodium levels go up, potassium levels go down, and when sodium levels go down, potassium levels go up. Potassium levels are also affected by a hormone called aldosterone, which is made by the adrenal glands.

Potassium levels can be affected by how the kidneys are working, the blood pH, the amount of potassium you eat, the hormone levels in your body, severe vomiting, and taking certain medicines, such as diuretics and potassium supplements. Certain cancer treatments that destroy cancer cells can also make potassium levels high.

A potassium level that is too high or too low can be serious. Abnormal potassium levels may cause symptoms such as muscle cramps or weakness, nausea, diarrhea, frequent urination, dehydration, low blood pressure, confusion, irritability, paralysis, and changes in heart rhythm.

Other electrolytes, such as sodium, calcium, chloride, magnesium, and phosphate, may be checked in a blood sample at the same time as a blood test for potassium.

Why It Is Done

Why It Is Done

A blood test to check potassium is done to:

  • Check levels in people being treated with medicines such as diuretics and for people having kidney dialysis.
  • Check to see whether treatment for too low or too high potassium levels is working.
  • Check people with high blood pressure who may have a problem with their kidneys or adrenal glands.
  • Check the effects of extra nutrition (total parenteral nutrition [TPN]) on potassium levels.
  • Check to see whether certain cancer treatments are causing too many cells to be destroyed (cell lysis). Cell lysis syndrome causes very high levels of some electrolytes, including potassium.
 How To Prepare

How To Prepare

In general, there's nothing you have to do before this test, unless your doctor tells you to.

 How It Is Done

How It Is Done

A health professional uses a needle to take a blood sample, usually from the arm.

 How It Feels

How It Feels

When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.

 Risks

Risks

There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.

 Results

Results

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

Many conditions can affect potassium levels. Blood potassium levels also vary with age. Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health.

High values

  • High blood potassium levels may be caused by damage or injury to the kidneys. This prevents the kidneys from removing potassium from the blood normally.
  • High blood potassium levels can also be caused by conditions that move potassium from the body's cells into the blood. These conditions include crushing injuries and heart attack.
  • Taking too many potassium supplements can also cause high levels of potassium in the blood.
  • Too much acid (pH) in the blood makes potassium levels higher by causing the potassium in the body's cells to "leak" out of cells and into the blood.
  • Some medicines, such as aldosterone antagonists and angiotensin-converting enzyme (ACE) inhibitors, can cause high potassium levels.

Low values

  • Low blood potassium levels can be caused by high levels of aldosterone (hyperaldosteronism) made by the adrenal glands.
  • Other conditions that can cause low blood potassium levels include severe burns, cystic fibrosis, alcohol use disorder, Cushing's syndrome, malnutrition, vomiting, diarrhea, and certain kidney diseases, such as Bartter's syndrome. Bartter's syndrome is a condition characterized by enlargement of certain kidney cells. It is more common in children and may be linked to an abnormally short stature (dwarfism). The cause of Bartter's syndrome is not fully known.
  • Medicines, such as diuretics, are a common cause of low potassium levels.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

To learn more about Healthwise, visit Healthwise.org.

© 1995-2024 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

Related Links

Medical Tests: Questions to Ask the Doctor

<cipublic-spinner variant="large"><span>Loading…</span></cipublic-spinner>

Page Footer

I want to...

Get an ID card File a claim View my claims and EOBs Check coverage under my plan See prescription drug list Find an in-network doctor, dentist, or facility Find a form Find 1095-B tax form information View the Cigna Glossary Contact Cigna

Audiences

Individuals and Families Medicare Employers Brokers Providers

Secure Member Sites

myCigna member portal Health Care Provider portal Cigna for Employers Client Resource Portal Cigna for Brokers

The Cigna Group Information

About Cigna Healthcare Company Profile Careers Newsroom Investors Suppliers The Cigna Group Third Party Administrators International Evernorth

 Cigna. All rights reserved.

Privacy Legal Product Disclosures Cigna Company Names Customer Rights Accessibility Non-Discrimination Notice Language Assistance [PDF] Report Fraud Sitemap Cookie Settings

Disclaimer

Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., Cigna HealthCare of Georgia, Inc., Cigna HealthCare of North Carolina, Inc., Cigna HealthCare of South Carolina, Inc., and Cigna HealthCare of Texas, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see a listing of the legal entities that insure or administer group HMO, dental HMO, and other products or services in your state). Accidental Injury, Critical Illness, and Hospital Care plans or insurance policies are distributed exclusively by or through operating subsidiaries of Cigna Corporation, are administered by Cigna Health and Life Insurance Company, and are insured by either (i) Cigna Health and Life Insurance Company (Bloomfield, CT); (ii) Life Insurance Company of North America (“LINA”) (Philadelphia, PA); or (iii) New York Life Group Insurance Company of NY (“NYLGICNY”) (New York, NY), formerly known as Cigna Life Insurance Company of New York. The Cigna name, logo, and other Cigna marks are owned by Cigna Intellectual Property, Inc. LINA and NYLGICNY are not affiliates of Cigna.

All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.

Selecting these links will take you away from Cigna.com to another website, which may be a non-Cigna website. Cigna may not control the content or links of non-Cigna websites. Details