endocrine and metabolic disorders
Hypokalemia
Introduction
Hypokalemia is serum potassium concentration<3.5 mEq/L (<3.5 mmol/L) caused by a deficit in total body potassium stores or abnormal movement of potassium into cells. The most common cause is excess loss from the kidneys or gastrointestinal tract. Intracellular shifts as well as certain medications can also cause hypokalemia. Clinical features include muscle weakness and polyuria; cardiac hyperexcitability may occur with severe hypokalemia. Diagnosis is by serum measurement. Treatment is giving potassium and managing the cause. (See also Overview of Disorders of Potassium Concentration .) 