This makes you cough and spit - just like a really bad cold. Chronic bronchitis is when this coughing and spitting continues for months at a time, and it keeps coming back every year. A lot of people with bronchitis have to breathe from special oxygen tanks so that their body cells can get the amount of oxygen they need to live.
Chronic bronchitis can lead to emphysema - another lung disease.
Like emphysema, chronic bronchitis is caused by smoking. Non-smokers hardly ever get it, so the best way to avoid having chronic bronchitis is to never start smoking. There is no cure for chronic bronchitis.