Potassium is one of the body's major ions.
The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential. Small changes in the extracellular potassium level can have profound effects on the function of the cardiovascular and neuromuscular systems. The kidney determines potassium homeostasis, and excess potassium is excreted in the urine. Severe hypokalemia is relatively uncommon. Incidence is equal in males and females.