What is the major cause of respiratory acidosis?

The major cause of respiratory acidosis is excessive carbon dioxide retention. This condition occurs when the body is unable to effectively expel carbon dioxide, which then accumulates in the bloodstream. Carbon dioxide in the body reacts with water to form carbonic acid, leading to a decrease in blood pH and resulting in acidosis.

Respiratory acidosis is often associated with conditions that impair lung function, such as chronic obstructive pulmonary disease (COPD), severe asthma, or any condition that reduces respiratory drive. In these cases, the usual exchange of gases in the lungs becomes compromised, resulting in a buildup of carbon dioxide rather than its normal elimination.

Other choices do not directly contribute to respiratory acidosis. For example, loss of carbon dioxide would lead to respiratory alkalosis instead, and inadequate oxygen intake does not create an acid-base imbalance; rather, it leads to hypoxia. Pneumonia, while it can lead to respiratory issues, is a specific condition that may result in respiratory acidosis if it causes significant impairment of ventilation, but it is not the primary mechanism. Hence, the most accurate cause consistently associated with this condition is excessive retention of carbon dioxide.