Which of the following conditions can lead to an increase in pCO2 levels in the body?

An increase in pCO2 levels in the body is primarily associated with hypoventilation. This condition occurs when there is insufficient ventilation to expel carbon dioxide (CO2) from the body, resulting in an accumulation of CO2 in the bloodstream. As breathing decreases or becomes ineffective, less CO2 is removed during exhalation, which leads to elevated levels of pCO2, a condition known as hypercapnia.

In contrast, hyperventilation, which involves rapid or deep breathing, typically reduces pCO2 levels as more CO2 is expelled than produced, leading to a decrease in its concentration in the blood. Excessive exercise can initially lead to increased CO2 production due to heightened metabolic activity, but if ventilation compensates adequately, pCO2 levels might not rise. Dehydration primarily affects fluid balance and does not directly influence CO2 levels in the same way that ventilation does. Thus, hypoventilation is clearly linked to increased pCO2 due to inadequate gas exchange in the lungs.