The most important thing to remember about shortness of breath is that you need to keep your thoughts and actions focused by using an organized approach. I recommend thinking anatomically. The differential diagnosis for this complaint is huge, and it’s really easy to make mistakes if you don’t develop a system. Also, you MUST calculate a Well’s Score and PERC criteria for your patients with shortness of breath. This is how you determine what tests to pick when you evaluate for pulmonary embolism. Learn this now, because your attendings will quiz you on this frequently during your clerkships.