24-Hour Urine Potassium Test

Chemical test that measures total amount of potassium element (K+) excreted in urine over 24-hour period. Potassium is main intracellular cation, playing crucial role in nerve and muscle function (including heart muscle). Reflects primarily efficiency of distal renal tubules in potassium reabsorption and excretion, process heavily influenced by aldosterone hormone and blood acid-base level.