Disorders of potassium homeostasis are common electrolyte abnormalities encountered in hospitalized patients. Hypokalemia and hyperkalemia have been estimated to occur in about 21% and 3% of hospitalized patients, respectively; though the morbidity and mortality associated with the latter is significantly higher. Potassium is a predominantly intracellular ion and the understanding of its dynamics between intra- and extracellular fluid milieus, along with its handling by the kidneys, is important in the diagnosis and treatment of potassium disorders. This article aims to provide a clinically relevant update on management of potassium disorders for internists.