Which symptom is commonly associated with both pneumonia and pulmonary embolism?

Fever is a symptom that commonly occurs in both pneumonia and pulmonary embolism. In pneumonia, fever typically develops as part of the body's immune response to the infection in the lungs. It is a natural reaction as the body tries to fight off the pathogens causing the infection.

In the case of pulmonary embolism, fever can also be present due to the inflammatory response triggered by the blocked blood vessels in the lungs, which can lead to an increase in body temperature. The presence of fever in both conditions can serve as an indicator of underlying disease processes and the body’s reaction, thus providing valuable information in a clinical assessment.

The other options do not commonly overlap between pneumonia and pulmonary embolism. Inability to empty the bladder is more associated with urinary tract or neurological issues rather than respiratory conditions. Paralytic ileus, which refers to a lack of movement in the intestines, is not a typical symptom of either of these respiratory conditions. Collapse of alveoli, or atelectasis, while it may occur in various respiratory conditions, is not a direct symptom observed in both pneumonia and pulmonary embolism. Therefore, fever stands out as the shared symptom relevant to both diagnoses.