Tobacco smoking
Chronic bronchitis is defined as a productive cough – one that produces sputum – that lasts for three months or more per year for at least two years. Many people with chronic bronchitis also have chronic obstructive pulmonary disease (COPD). Tobacco smoking is the most common cause, with a number of other factors such as air pollution and genetics playing a smaller role. Treatments include quitting smoking, vaccinations, rehabilitation, and often inhaled bronchodilators and steroids. Some people may benefit from long-term oxygen therapy.