Bronchitis can be caused by a few different things. You can get bronchitis from a cold virus that you have, if the virus moves into your lungs. Usually you have to take over the counter medicine and let it run its course. You can also get a bacterial bronchitis that can start from a cold, or other bacterial infection. Your Dr. will prescribe an antibiotic for this, as the bacterial bronchitis may turn into pnuemonia.