In 2013 she appeared in a TED video entitled "How to make stress your friend" (See video below).
In the video the following two main points were made by her and caused quite a stir:
Firstly, she claimed that according to a study people who think positive thoughts about their stress are not negatively affected by the stress because their blood vessels do not constrict. Therefore their bodies cope better with the stress conditions they find themselves in.
Secondly she claimed that Oxytocin is a stress hormone, excreted during stress to regenerate the physical damage stress could have on the body.
If she is right it would mean what society teaches us about stress is wrong and it would also mean that we should more often accept the fact that the way we think influences our physical beings.
What Dr Mcgonigal is saying is that if you are experiencing stress you should view it as your body reacting in the correct way and that the reaction is there to help you. As soon as you see the stress as negative you become sicker.
With this in mind, imagine the strength we have to change our bodies physically by means of our thinking.