The young patient's symptoms are nonspecific but there are questions that should be asked to help narrow the differential diagnosis - which ones?
History of present illness: A man in his mid-20’s presents to the hospital emergency department for 2 days of feeling lightheaded and short of breath. He also has a slight cough plus intermittent chills and a mild headache. He denies any fever or known COVID/flu exposure at either of his two jobs, one as a welder and the other as a painter. He is single and lives alone.
Vital signs & physical examination: Vital signs are normal. Physical examination is normal
Initial diagnostic testing
Imaging: CXR normal
Which of the following questions is important to ask?