My way of deciding if its anxiety or not is if it gets better when I'm busy thinking of something else, or goes completely away.
For instance if you are having chest pains and you get busy doing something else and realize, hey the chest pains went away, and then you realize that you were worried and they come back--anxiety.
Same with any other symptom or pain. If you have abnormal blood work, symptoms that don't away no matter what you do, even when you sleep or when you are thinking of other things-dig and don't take no for an answer.
But if it only gets worse when you think about it, its anxiety.