The bronchial tubes carry air into the tiny branches and smaller cells of the lungs. In bronchitis, the tubes become sore and you develop a deep cough. Bronchitis caused by bacteria can be treated with antibiotics, but there's no drug treatment for the more common kind caused by a virus. A bout of bronchitis may involve a couple of weeks of coughing (with no laughing allowed), weakness, and loss of energy and interest in doing things. Apart from that, bronchitis is rarely serious—at least if it doesn't progress to pneumonia.