What risk is associated with immobility and can lead to respiratory issues?

Immobility can significantly increase the risk of pneumonia due to the reduced ability to take deep breaths and the less frequent movement of the chest wall. When a person is immobile, the secretions in the lungs can become stagnant, making it easier for bacteria to grow and leading to pulmonary infections such as pneumonia. Additionally, immobility can prevent the effective clearing of mucus from the lungs, further contributing to respiratory complications.

The other options, while they can be associated with immobility, do not directly link to respiratory issues in the same way that pneumonia does. Risk of fainting is often related to cardiovascular factors rather than directly to the respiratory system. Risk of dehydration typically concerns fluid intake and output rather than respiratory health. Even though the risk of fractures can be a significant concern for immobile patients, it pertains more to musculoskeletal health and does not specifically lead to respiratory issues like pneumonia does.