What changes occur in electrolyte levels after prolonged vomiting?

After prolonged vomiting, the body experiences significant shifts in electrolyte levels due to the loss of stomach contents, which are rich in hydrochloric acid (HCl) and other electrolytes. Specifically, when someone vomits, they lose significant amounts of gastric acid, which contains a high concentration of hydrogen ions and chloride ions. This loss leads to a decrease in both potassium and chloride levels.

The process also often triggers an increase in bicarbonate levels in the blood, as the body attempts to compensate for the acid loss, leading to metabolic alkalosis. However, the key aspect related to potassium is that it is typically lost through vomiting, particularly when it is excessive or prolonged. Therefore, a decrease in potassium occurs because the body is not only losing gastric contents but is also unable to absorb potassium effectively from the gastrointestinal tract during this time.

This physiological context clarifies why a decrease in both potassium and chloride levels is the most accurate answer in the scenario of prolonged vomiting, highlighting the body's compensatory mechanisms and the impact of electrolyte imbalance on overall health.