DEAR DOCTOR K: I had a chest cold. I feel better, but I'm still coughing a lot. This has been going on for more than three weeks. Why am I still coughing?
DEAR READER: Most likely, you had bronchitis, an inflammation of the lining of the bronchial tubes. Bronchitis is usually caused by an infection -- viral or bacterial. The bronchial tubes are air passages connecting the lungs to the windpipe. Bronchitis usually starts with an upper respiratory illness that spreads from the nose and throat down into the airways.