Which term describes the retention of CO2 in the blood?

The retention of CO2 in the blood is referred to as hypercapnia. This condition occurs when there is an increase in the carbon dioxide (CO2) levels in the bloodstream, which can happen due to various factors such as respiratory failure, chronic obstructive pulmonary disease (COPD), or inadequate ventilation. Elevated CO2 levels can lead to respiratory acidosis, affecting the body’s acid-base balance and causing symptoms such as confusion, headaches, and shortness of breath.

Understanding related terms can help clarify why hypercapnia is the correct choice. Hypoxia refers to a deficiency of oxygen in the tissues, which is not directly related to CO2 levels. Hyperoxia indicates an excess of oxygen in the tissues or blood, which is also not concerned with carbon dioxide retention. Hypocapnia, on the other hand, means reduced levels of carbon dioxide in the blood, often resulting from hyperventilation, and does not relate to retention of CO2. Thus, hypercapnia is the clearest and most accurate term for this phenomenon.