This test measures the amount of potassium in the fluid portion (serum) of the blood. Potassium (K+) helps nerves and muscles communicate. It also helps move nutrients into cells and waste products out of cells.
Potassium levels in the body are mainly controlled by the hormone aldosterone.
To check for an electrolyte imbalance, check certain medications that affect potassium levels, particularly diuretics, heart medications, and high blood pressure medications, diagnosing heart problems and high blood pressure, to diagnose kidney disease check for metabolic acidosis, to diagnose alkalosis, finding the cause of a paralysis attack
A blood sample is needed. Most of the time blood is drawn from a vein located on the inside of the elbow or the back of the hand.
Many medicines can interfere with blood test results. Your health care provider will tell you if you need to stop taking any medicines before you have this test. Do not stop or change your medicines without talking to your provider first.
The normal range is 3.7 to 5.2 mEq/L (3.70 to 5.20 millimole/L).
Note: mEq/L = milliequivalents per liter; millimol/L = millimoles per liter.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.