The first/most important thing to point out is that hypnotherapy DOES NOT involve some magical taking over of your mind. Paul McKenna's TV show and other stage hypnotists have an awful lot to answer for!
Hypnosis cannot make you do anything you do not want to do. My clients remain fully in control throughout their relaxing therapeutic hypnosis experience.
Hypnosis is a completely natural state which occurs between wakefulness and sleep. We experience it every time we wake or fall asleep, but we are mostly unaware.
This trance state is achieved by deep relaxation of both the mind and the body using guided concentration. When this is achieved, the boundary between the conscious and the unconscious minds begins to blur and then the unconscious becomes open to receiving new messages. This enables you to look at deep rooted issues such as phobias, fears and habits - and let them go.
Hypnosis is not mind control, it is about offering suggestions into your subconscious.