One definition could be as follows:

Hypnosis is a state of mind in which suggestions are acted upon considerably more powerfully than is possible under normal conditions.
When in hypnosis – trance, we suppress the power of conscious criticism. One’s focus of attention is narrower and one’s level of awareness on a focal point is considerably higher than if one was fully awake. During the heighted focus and awareness, suggestions appear to go directly into the subconscious mind. In hypnosis you can control areas and aspects of yourself, that often appear to be out of contact of your conscious mind.

If what I have said has made you sceptical, just sit down and quietly, but consciously, endeavour to slow down your heart beat, or to raise the temperature of your hand. These are examples of subconscious physical changes that would normally be out of your conscious control. In hypnosis you can make changes in the chemical, physical, psychological and emotional part’s of yourself.

Most hypnotherapist’s will agree that all hypnosis is really self hypnosis. A hypnotherapist can normally help you to guide and develop the trance – altered states, but you are always in control. It is your hypnosis, trance, altered states, your healing.

The question is often asked if someone can be made to do something against their will. However experience has shown that client’s – patient’s will only follow those hypnotic suggestion’s that are in their own basic interest’s. They will either ignore the direction’s from the therapist’s, or if pressured to comply, they will come out of the trance state. Everyone, will under hypnosis, follow their own ethics and conscience. They cannot be made to do anything that they would not ordinarily do in their everyday life. There is no relinquishing of your will power or freewill, under hypnosis. You still understand what is right for you and what is definitely not the case.

The hypnotic happening is a naturally occurring state that virtually everyone, is especially with practice, can learn to use in self hypnosis for achieving objectives that might otherwise be too difficult, or even impossible, to achieve with the conscious mind.