A 55-year-old female presents with shortness of breath and swelling in her right leg. What condition should you suspect?

The presentation of shortness of breath combined with swelling in one leg is highly suggestive of a pulmonary embolism. In this scenario, the shortness of breath indicates that there may be an issue with the lungs or the circulatory system, and the unilateral leg swelling points towards a possible deep vein thrombosis (DVT) that could have led to the pulmonary embolism.

A pulmonary embolism occurs when a blood clot, often originating from the deep veins in the legs, breaks loose and travels to the lungs, obstructing blood flow and causing symptoms such as sudden onset of shortness of breath, chest pain, and potentially leg swelling. In this case, the patient's leg swelling may suggest the presence of a DVT, which is a common precursor to pulmonary embolism.

Other conditions listed, such as congestive heart failure, could cause shortness of breath but typically would not cause unilateral leg swelling in isolation. Chronic obstructive pulmonary disease (COPD) could also lead to shortness of breath but is not directly associated with leg swelling. Lastly, pneumonia may cause respiratory distress but is unlikely to result in unilateral leg edema. Therefore, the combination of shortness of breath and swelling in one leg paints a clearer clinical picture consistent with a diagnosis of