about a week ago, my son was in his car and he stretched and his chest below the left nipple started to hurt and it was difficult for him to breath fully in and out.  I told him to take 4 to 5 deep breaths to see if that would help if it was gas.  He says that it has gradually stopped hurting as bad, but still hurts some when he breaths and when he bends or stoops over.  He is also coughing, but no mucus.  could he have bronchitis?
Hi there, This could be bronchitis, but most likely this is due to atelectasis, or collapse of the smaller airways in the lungs due to his inability to take deep breaths. I'd recommend he really work on talking deep breaths, which will cause him to cough and will open up his deep airways.  The other possibility is that he has a partially collapsed lung (pneumothorax) which would also cause him to cough. If he continues to have coughing and this is not improving, I recommend he undergo a chest x-ray, which is a good test to show any abnormalities he may have incurred secondary to the car accident. I hope this answers your questions. Please feel free to contact me should you have any further questions.