Hypoventilation leads to which acid-base disorder?

Hypoventilation leads to which acid-base disorder?

• A. Respiratory alkalosis
• B. Respiratory acidosis
• C. Metabolic alkalosis
• D. Metabolic acidosis

Answer: (B)

When ventilation is reduced, the body cannot eliminate CO2 effectively, causing CO2 to rise in the blood. CO2 combines with water to form carbonic acid, which dissociates into hydrogen ions and bicarbonate, increasing acidity and lowering the pH. This pattern defines a respiratory acidosis. The body may attempt renal compensation by increasing bicarbonate reabsorption and hydrogen ion excretion, but that response develops over hours to days. By contrast, if ventilation were increased (hyperventilation), CO2 would drop and pH would rise (respiratory alkalosis). Metabolic disturbances involve changes in bicarbonate or non-CO2 acids, not primary CO2 retention, so they produce different acid-base patterns.

When ventilation is reduced, the body cannot eliminate CO2 effectively, causing CO2 to rise in the blood. CO2 combines with water to form carbonic acid, which dissociates into hydrogen ions and bicarbonate, increasing acidity and lowering the pH. This pattern defines a respiratory acidosis. The body may attempt renal compensation by increasing bicarbonate reabsorption and hydrogen ion excretion, but that response develops over hours to days. By contrast, if ventilation were increased (hyperventilation), CO2 would drop and pH would rise (respiratory alkalosis). Metabolic disturbances involve changes in bicarbonate or non-CO2 acids, not primary CO2 retention, so they produce different acid-base patterns.