24 Hour Urine Potassium(K+)

You should get a 24-hour urine potassium test if your blood potassium is abnormally low or high, or if you have muscle weakness, cramps, fatigue, or irregular heartbeat. It is also recommended for high blood pressure, adrenal disorders, or kidney disease, for people taking diuretics, and for evaluating kidney stone risk and dietary potassium intake.

To prepare for a 24-hour urine potassium test, discard your first morning urine and note the time. Then collect all urine for the next 24 hours, including the next morning’s first sample, and keep it refrigerated. Follow your usual diet unless advised otherwise, and inform your doctor about diuretics, potassium supplements, laxatives, or blood pressure medicines.

No, fasting is not required for a 24-hour urine potassium test. You should eat your usual diet during the collection period unless your doctor advises otherwise, as the test reflects your normal potassium balance. Drink fluids normally, and collect every urine sample over the full 24 hours.