Hypokalemia is defined as serum K+ level of <3.5mmol/L. Hypokalemia can occur with normal total body K+ as a result of shifts of K+ into intracellular pools or with total body K+ depletion through deficient intake or excessive renal or gastrointestinal excretion The presence of an abnormally small concentration of potassium ions in the circulating blood; occurs in familial periodic paralysis and in potassium depletion due to excessive loss from gastrointestinal tract or kidneys