Metabolic alkalosis is a common disorder, accounting for half of all acid-base disturbances in hospitalized patients. It is the result of an increase in bicarbonate production, a decrease in bicarbonate excretion, or a loss of hydrogen ions. Most causes of metabolic alkalosis can be divided into 4 categories: chloride depletion alkalosis, mineralocorticoid excess syndromes, apparent mineralocorticoid excess syndromes, and excess alkali administration. Treatment is usually supportive and based on cause of the alkalosis.