Bronchitis is an illness of the bronchial tubes, the air pipes that take air into your lungs. The tubes become inflamed — swollen and sore — and you cough, often a lot, and you may bring up mucus. Acute bronchitis often follows a cold and then goes away. Chronic bronchitis hangs on, and is common in people who have smoked for years. In everyday English people may just say a chest infection or a bad cough; bronchitis is the clearer, slightly medical name. Though actually, you cannot always tell it from a heavy cold, or from pneumonia, just by how miserable you feel — pneumonia is an infection of the lung tissue itself, not only the tubes. A doctor sorts that out. It is not a tickle in the throat; the trouble sits lower, in the chest.