You'd Be surprised how many people who are fine think theres something wrong with them.

http://www.theguardian.com/commentisfree/2013/oct/11/healthcare-anxiety-doctors-non-beneficial-treatments

In this article a man came to his doctor to get a Ct scan due to the fact that he was having bad headaches and thought he had a brain clot. As the doctor looked through history nothing could be wrong with this man. But the man kept insisting and the doctor was confused on what to do.To either tell him to just keep a positive mind or give the scan and increase his chance with radiation. The doctor refused him which ended up being fired from this patient. The reason why this is such a problem is because alot of people are thinking there is somthing wrong with them when there isnt which means that all these people have server anxiety.