Bronchitis is a condition in which you can have an illness that is both infectious and one that is noninfectious. In most cases, it is a virus that causes bronchitis to happen. This virus is generally the same type that causes a common cold to happen in most people.On the other hand, bronchitis can also be a condition that is caused by the pollutants in the air that you breathe including from cigarette smoke. Smog and chemicals that are used to clean...