Metabolic acidosis is characterized by which of the following?

• A. Increased hydrogen ion retention and decreased bicarbonate
• B. Increased bicarbonate retention
• C. Increased CO2
• D. Decreased hydrogen ions

Answer: (A)

Metabolic acidosis happens when there’s too much acid in the body or a loss of bicarbonate, so hydrogen ion concentration in the blood goes up and bicarbonate goes down, lowering the pH. The body tries to compensate by blowing off CO2 through faster breathing, which lowers CO2 levels rather than raises them. That’s why the option describing increased hydrogen ions and decreased bicarbonate best fits metabolic acidosis. The other ideas describe bicarbonate gain (alkalosis), increased CO2 (a sign of respiratory issues), or decreased hydrogen ions (alkalemia), none of which define metabolic acidosis.