What happens to blood carbon dioxide levels during hypoventilation?

• A. They decrease
• B. They remain stable
• C. They increase
• D. They fluctuate

Answer: (C)

During hypoventilation, the rate and depth of breathing decrease, which leads to an accumulation of carbon dioxide (CO2) in the bloodstream. Under normal circumstances, ventilation helps to regulate carbon dioxide levels by removing CO2 as it is produced by metabolic processes. However, with hypoventilation, there is insufficient exchange of gases, causing CO2 to be retained in the blood.

As a result, the partial pressure of carbon dioxide in the arterial blood rises, leading to a condition known as hypercapnia. This increase can impact the body's acid-base balance as CO2 is converted to carbonic acid in the blood, resulting in a decrease in blood pH (acidosis). Thus, the correct answer highlights that blood carbon dioxide levels increase during hypoventilation, reflecting the retention of CO2 due to inadequate ventilation.