Bronchitis is an inflammatory infection of the airways following a viral or bacterial infection. The airways affected start from the nose and include the windpipe (trachea) and the main large air tubes (bronchi) down into the lungs. The inflammation may only be of a short (acute) duration with fairly swift, uncomplicated recovery. Sometimes bronchitis follows a long-term (chronic) course. Chronic bronchitis signals serious lung disease that cannot be cured although its progress can be reduced.