I've learned to be very careful who I tell at work, as the sweet ladies there worry themselves sick about me if I say anything. Before I learned this, however, I would just look at them and, after about the fourth day say "Do I LOOK like I'm sick?" And they would have to agree that no, I look better than I did before. I always do, except maybe some dark circles under my eyes, which can be covered up with cosmetics if need be.