What is the main cause of atelectasis?

Atelectasis is primarily defined as a collapse of the lung or part of the lung, leading to reduced gas exchange and ventilation in the affected area. The main cause of this condition is a blockage of the bronchus or bronchiole, which can be due to a variety of factors such as mucus plugs, foreign bodies, or tumors. When a bronchus or bronchiole becomes obstructed, the air trapped within the alveoli cannot be replenished, resulting in the collapse of these small air sacs.

This obstruction prevents air from entering the lung tissue, which causes surrounding alveoli to deflate and leads to atelectasis. The importance of recognizing the blockage as the primary cause lies in understanding the potential for resolution—removing the blockage can often restore normal lung function.

Other options, while they can impact lung health and contribute to respiratory issues, do not directly cause atelectasis. For example, an infection can lead to inflammation and fluid accumulation but does not necessarily block airways in the same way a physical obstruction does. Similarly, obstructing blood vessels would not lead to atelectasis since it focuses on blood circulation rather than airflow in the lungs. Excessive coughing can be a response to respiratory distress but is not a direct caus