Colds, the flu, and sinus infections have such similar symptoms that it can be tough to know what truly ails you. That said, a few subtle differences can tip you off. Diagnose yourself using this chart. | Health.com
I never understood why since childhood my mother would say, "you have dark circles under your eyes" as an accusation, like I was choosing to be sick and could do anything about it. Probably why I feel guilty 24/7 for not "being" enough.