I have a patient who has fairly extensive COPD, by PFTs, imaging, and symptoms, however, she has never smoked.  She has some secondhand smoke exposure, but none at all in the last 15 years.  She was not doing well on her current management.

When things aren’t adding up, reconsider the diagnosis. Everytime someone hands you a diagnosis, reconsider the diagnosis. When you are randomly thinking about a patient on your drive home, reconsider the diagnosis.

What else could my patient have, if COPD is not the answer?  Here’s a quick differential diagnosis of COPD. There are other things to consider, but these can mimic COPD often enough that they should come to your mind in particular situations. As usual, a good history and physcial can help you sort these out.