How are you? I commend you for your smoking cessation and it is good that the initial diagnostic test results were fine. Bronchitis or inflammation of the lining of the bronchial tubes may develop from a cold or other respiratory infection or caused by smoking or constant irritation such as dust or air pollution. The goal of treatment is to relieve symptoms including self-care treatments such as getting more rest, drinking fluids, or breathing in warm, moist air. To prevent this, it is usually advised to avoid cigarette smoke. f it persists, you may need to have this evaluated further. Take care and do keep us posted.