How to Check Potassium Levels

Typically, a person keeps their potassium level normal by eating a healthy diet full of leafy greens, tomatoes, potatoes, bananas and mushrooms. The body uses potassium to control blood pressure and keep the metabolism going. When kidneys do not function properly or blood pressure is too high, knowing your potassium level is important. Doctors perform a blood test to check for a high or a low potassium level.

Things You'll Need

• Tourniquet
• Syringe
• Vial or tube
• Blood lab
• Medical cloth

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Instructions

• 1

  Before you take the test, discuss with your doctor any medications you are taking. Some medications change the potassium level in your blood. For instance, drugs like epinephrine and histamine raise the potassium level. Potassium levels can lower when you take insulin or laxatives. If you are taking one of these drugs, your doctor might request you stop taking the drug for the test.

• 2

  Clean the area to draw blood from. Use an antiseptic to kill germs near the vein chosen for the blood draw.

• 3

  Apply a tourniquet to the upper arm. Medical staff wraps an elastic band or arm cuff around the upper arm. The wrap applies pressure on the bloodstream, readying the vein in the lower arm to exude blood into a vial through a needle.

• 4

  Place a needle in a vein in the inside of the elbow or back of the hand. A staffer carefully inserts the needle into the bloodstream.

• 5

  Draw blood into a vial. Once the medical staff inserts the needle, blood collects in a vial or tube on the needle. During collection, the staff removes the tourniquet on your arm. The blood fills the vial or tube. Your aid removes the needle.

• 6

  Cover the area to stop the bleeding. Medical staff applies clean cloth to the area, with pressure to stop the flow of blood.

• 7

  Test the blood to assess the potassium level. Medical staff takes the blood to the laboratory for testing. The test measures the level of potassium in the blood sample.

• 8

  Review the test results to determine if the level is within normal range. Your doctor reviews the test results to tell you whether the the potassium level is normal, high or low. The normal range is 3.7 to 5.2 milliequivalents per liter. A high level, hyperkalemia, can indicate poor regulation by the kidneys, which happens during kidney failure. A low level, hypokalemia, can exist in patients with poor nutrition or diarrhea. The doctor will discuss any possible conditions.