34yr old male, never smoked. intermittent sob, 2 docs say lungs sound normal, x-ray results show normal lungs. sometimes feel tightness in chest/throat. worse after exercise, but resolves with inhaler. lung cancer?

Extremely unlikely: SOB that is worse after exercise and relieved with inhalers is likely due to asthma- or "reactive airway disease."

Pulmonology : If the inhaler is Albuterol and relieves symptoms, you may have asthma. Please see your physician for a review of possible triggers and a referral to a Pulmonary specialist. In the meantime, use the inhaler as directed.