My husband has a history of lung cancer in his family. His father, grandfather, and uncle passed from it in their mid forties. He is a 30 year old healthy male. He is a Zambian who has lived here for 10 years. His relatives passed in Zambia. There is no history of smoking in his family and he has never smoked. He is in IT. Lately he has shortness of breath and pain in the middle of his chest after we have intercourse (strange, I know). He ran a marathon in 3:10 yesterday and faintly felt it. He rarely feels it during running, just after intercourse. He does not have a cough or wheezing. He is all around very healthy. What would you recommend we do? He had an EKG in May because we thought this was a heart issue and it came back that he was perfectly normal. Please advise. Thank you very much!