Thanks for your question on Healthcare Magic. I can understand your concern. Chest pain, coughing, bad smell breath and breathing difficulty in a smoker is mostly due to lung disease like lung infection and bronchitis. So better to consult pulmonologist and get done clinical examination of respiratory system, chest x ray and PFT (Pulmonary Function Test). Chest x ray is needed to rule out lung infection. PFT is must for the diagnosis of bronchitis. You will mostly improve with antibiotics and inhaled treatment. In any case smoking cessation is must. Don t worry, you will be alright with all these. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.