This test measures the level of potassium in the blood. Potassium is an electrolyte, which is a mineral that carries an electric charge. Minerals have many important functions in the body. This includes playing a key role in muscle, heart and digestive function. When potassium levels are abnormal, normal bodily functions can be affected.

Potassium is found in the foods we eat. It is absorbed into the blood from the intestines and then transported to the rest of the body via the bloodstream.

• The kidneys filter excess potassium out of the blood. The filtered potassium is eliminated from the body in the urine.
• Potassium levels can become abnormal (high or low) for many reasons.

Hypokalemia occurs when the level of potassium in the blood is low. When the level of potassium is high, the condition is called hyperkalemia. More often, hypokalemia is caused by the body losing potassium due to:

• Severe diarrhea and vomiting
• Use of certain medications (i.e., diuretics, laxatives or steroids)
• Overuse of enemas
• Certain kidney disorders
• Excessive sweating
• Burns
• Severe low body temperature (hypothermia)
• Alcoholism and malnutrition

Kidney disease is the most common cause of hyperkalemia. Other causes include:

• Use of certain medications that cause the body to retain potassium
• A decrease in the hormone aldosterone, which helps regulate potassium and sodium balance
• Medical conditions that cause too much potassium to leave the cells and enter the bloodstream; e.g., when the blood becomes too acid (acidosis)
• Trauma, especially crushing injuries or burns
• Use of potassium supplements when they are not needed

Hypokalemia is often associated with no symptoms until the potassium level is extremely low. When symptoms occur, they can include:

• Fatigue
• Muscle weakness or cramping, usually in the legs
• Constipation, nausea, vomiting or abdominal cramps
• Abnormal heart rate or rhythm
• Shallow breathing
• Urinating frequently and increased thirst
• Hallucinations or psychosis

Hyperkalemia also does not usually cause symptoms until potassium levels are very high. Symptoms can include:

• Fatigue
• Weakness
• Numbness or tingling
• Paralysis
• Abnormal heart rate or rhythm

Severe hypokalemia and hyperkalemia can both lead to death.

In an adult, the blood sample is usually taken by placing a needle in a vein in the arm or by pricking a finger. In a baby or child, the sample may be taken by pricking a finger or heel.

• No special preparation is needed.
• Ask your healthcare provider if you need to stop taking any medicines before the test.
• Do not stop taking any medicine unless your healthcare provider tells you to do so.

This care path's costs do not include the charge to draw blood from a vein (venipuncture). There will only be one charge to draw blood, even if multiple tests are being performed on the samples that are taken.

What should I ask my healthcare provider before having this test?

• Is there any special preparation for the test? (If so, get clear instructions on what you need to do.)
• What is the reason for the test? Will the test results change my treatment plan? If not, do I need the test?
• Why is my potassium level low or high?
• How often do I need to get my potassium level checked?
• Do I need to take supplements?
• Do I need to follow a special diet?

Source UHC.com

Also known as:

Potassium Test

Laboratory Work

Potassium Blood Test

Blood Test for Potassium

Level of Potassium