This famous quote was made by Chevalier Jackson in the Boston Medical Quarterly in 1865.1 At the time, Jackson, an otolaryngologist, was concerned about foreign body aspiration causing wheezing and being misdiagnosed as asthma. Today, this adage reminds us that there are many causes of wheezing and shortness of breath besides the common and classic diagnosis of asthma. Among these causes is COPD. In fact, COPD is probably one of the most common diagnoses made in the older patient with a smoking history who complains of shortness of breath, wheezing, or chest tightness. However, COPD is frequently underdiagnosed and overdiagnosed. Patients are underdiagnosed when spirometry is not used to search for objective evidence of obstruction, and patients are overdiagnosed when spirometry is not used to confirm the “obstruction” in COPD. Overdiagnosis mislabels the patient with a disease they do not have, which can result in inappropriate prescription and use of costly medications that may have side effects. In addition, the focus on COPD shifts attention away from the possibility of other causes of the patient’s symptoms, such as obesity, deconditioning, heart disease, or depression, which may lead to a worsening of their true underlying condition.