Alternative name: Urine potassium
Definition: The potassium urine test measures the amount of potassium in a certain amount of urine.
How the Test is Performed
After you provide a urine sample, it is tested in the lab. If needed, the health care provider may ask you to collect your urine at home over 24 hours. Your provider will tell you how to do this. Follow instructions exactly so that the results are accurate.
How to Prepare for the Test
Your provider may ask you to temporarily stop taking any medicines that may affect the test results. Tell your provider about all the medicines you take, including:
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Potassium supplements
- Water pills (diuretics)
DO NOT stop taking any medicine before talking to your provider.
How the Test will Feel
This test involves only normal urination. There is no discomfort.
Why the Test is Performed
Your provider may order this test if you have signs of a condition that affects body fluids, such as dehydration, vomiting, or diarrhea.
It may also be done to diagnose or confirm disorders of the kidneys or adrenal glands.
The usual range for a person on a regular diet is 25 to 125 mEq/L per day. Lower or higher urinary level may occur depending on the amount of potassium in your diet and the amount of potassium in your body.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
A higher than normal urine potassium level may be due to:
- Diabetic acidosis and other forms of metabolic acidosis
- Eating disorders (anorexia, bulimia)
- Kidney problems, such as damage to kidney cells called tubule cells (acute tubular necrosis)
- Low blood magnesium level (hypomagnesemia)
- Muscle damage (rhabdomyolysis)
Low urine potassium level may be due to:
- Certain medicines, including beta blockers, lithium, trimethoprim, potassium-sparing diuretics, or nonsteroidal anti-inflammatory drugs (NSAIDs)
- Adrenal glands releasing too little hormone (hypoaldosteronism)
There are no risks with this test.
Batlle D, Chen S, Haque SK. Physiologic principles in the clinical evaluation of electrolyte, water, and acid-base disorders. In: Alpern RJ, Orson WM, Caplan M, eds. Seldin and Giebisch’s The Kidney. 5th ed. Waltham, MA: Elsevier Academic Press; 2013:chap 74.
Kamel KS, Davids MR, Lin S-H, Halperin ML. Interpretation of electrolyte and acid-base parameters in blood and urine. In: Skorecki K, Chertow GM, Marsden PA, Taal MW, Yu ASL, eds. Brenner and Rector’s The Kidney. 10th ed. Philadelphia, PA: Elsevier; 2016:chap 27.