Well, what did your doctor tell you about that? Did your doctor state you have a medical problem, or that you are healthy? When you got a second opinion, what did the doctor say then? If you find you are going to multiple doctors and getting multiple medical tests, only to be told by the doctor that you are healthy, then maybe you should start thinking that something is wrong- with your mental health. The following video details how hypochondria (health anxiety) develops, and how CBT can be helpful: