Participants who are either being or anticipate being discharged to their usual residence from the ER will be enrolled while still in the ER. Participants who were discharged to their usual residence may be contacted by telephone and enrolled up to 24 hours later, if willing to return to the Medical Center for study initiation. Hospitalized patients will be enrolled within the first 48 hours. Study physicians and coordinators will be on call to capture people at presentation, prior to steroids and antibiotics, if possible. However, clinically indicated treatment will not be delayed to permit enrollment or collection of research samples. Participants will be questioned about the status of five respiratory symptoms (dyspnea, cough, sputum production, sputum viscosity, sputum purulence) using a published Respiratory Symptom score instrument. Each symptom will be scored for severity using the following three-point scale: 1) Usual level; 2) Somewhat worse than usual; 3) Much worse than usual. An acute exacerbation of chronic bronchitis (AECB) will be defined symptomatically as a minor worsening (score of 2) for two or more symptoms, or a major worsening (score of 3) for one or more symptoms.