I'll try to come back and add one a day.
These are just some observations I've made with my own (primarily) health-related anxiety and cardiophobia. Feel free to chime in with your own!
1. When I'd be having chest pains, dizziness, arm pain, general over-sensitivity (even if it was quite bad) I've noticed that as soon as an unexpected distraction happens it goes away. Imagine something like walking along the street, feeling VERY anxious, concentrating on just getting through the next 5 minutes, and then a lady slips on the stairs and drops her bags on her way to the car. You totally snap out of your self-absorption and help. As you are walking away, you feel fine. If you were having actual chest pain instead of referred, imagined or embellished pain, it would likely not go away just because you thought of something else. This is also true of stubbing your toe, slamming your arm into the bureau as you walk past...or even having to pee really badly. I remember loving it when I had to pee and couldn't, because I knew my mind was so busy trying not to have me piss my pants that it couldn't dream shit up to freak me out.