How to Test for Low Potassium

Potassium (K), an electrolyte, helps maintain balance in the body. It helps with nutrient dispersal and waste removal at the cellular level and with communication between muscles and nerves. Extremely low potassium (hypokalemia), from either poor nutrition or the result of another serious medical condition, can cause a wide range of symptoms (irregular heartbeat, paralysis, thirst, muscle weakness) and even death. Potassium levels are tested via blood test with low potassium typically recognized as a blood serum level lower than 3.7 mEq/L (milliequivalent per liter).

Instructions

• 1

  Take your doctor's request for a potassium blood test (also known as "K+" or "hypokalemia test") or an electrolyte panel that includes potassium to a laboratory.

• 2

  Submit the paperwork to the laboratory receptionist. Answer any questions and then wait for your turn. If your doctor also requested a urine potassium test, provide that sample at this time.

• 3

  Confirm any information that the laboratory technician (phlebotomist) asks when called for your test.

• 4

  Offer an arm to the phlebotomist to try first. The phlebotomist will wrap a band around the top of your arm to force blood into the vein and will then wipe the vein area with antiseptic to kill any germs. The phlebotomist may also advise you to make a fist at this time.

• 5

  Turn your head away as the phlebotomist inserts the needle into your arm if you cannot stand the sight of blood or think you may tense or jerk your arm. The blood will flow into a specialized collection vial and then the phlebotomist will remove the band around the top of your arm.

• 6

  Press your fingers firmly to the cotton pad that the phlebotomist places on the test site after removing the needle to apply pressure and cut off the flow of blood at the insertion point. The phlebotomist will provide an adhesive bandage or non-adhesive wrap once the blood flow stops.