What is a common cause of metabolic alkalosis?

Metabolic alkalosis is a condition characterized by an increase in blood pH due to a loss of hydrogen ions or an accumulation of bicarbonate. One of the common causes of metabolic alkalosis is vomiting. When a person vomits, especially if it is prolonged or severe, there is a significant loss of gastric acid. Gastric acid contains hydrochloric acid (HCl), which contributes to the body's overall acidity. The loss of this acid leads to a decrease in hydrogen ions in the bloodstream, raising the blood pH and resulting in metabolic alkalosis.

In this context, while other conditions such as severe dehydration, excessive exercise, and hypoxia may lead to various acid-base imbalances, they do not primarily cause metabolic alkalosis in the same way that vomiting does. For instance, dehydration can lead to concentration of acids but is not directly responsible for causing an alkalotic state. Excessive exercise typically results in lactic acidosis due to muscle metabolism. Hypoxia affects the body’s oxygen levels but does not fundamentally lead to the same biochemical changes seen in metabolic alkalosis.

Therefore, vomiting stands out as a clear and common cause of metabolic alkalosis due to the direct loss of acidic gastric secretions.