hyp·no·sis /hipˈnōsis/ Noun
A heightened state of suggestibility, such that the suggestions given are accepted as being true and effect the beliefs, habits, perceptions and behaviors of an individual.
How Does Hypnosis Work?

Hypnosis can be explained this way...
When a person is in a relaxed state, their brainwave activity slows from Beta to Alpha/Theta brain wave activity.
When in this hypnotic state, the subconscious mind is 88% more alert then in a conscious state, and thus, more receptive to suggestion.
The conscious mind is able to be bypassed in order to make suggestions to the subconscious mind.
The subconscious mind then accepts these suggestions and creates the behavioral changes or body changes in order to achieve the given suggestions.
Related Links
Hypnosis Works...Here's Proof:
Facts about hypnosis from current research findings.
http://hypnosiswest.com/hypnosis-works.html
SCIENTIFIC AMERICAN
Scans Show How Hypnosis Affects Brain Activity
http//www.scientificamerican.com/article.efm?id=scans-show-how-hypnosis-a
HYPNOSIS WORKS
Dr. Wesley Anderson
Brain Scans Show That Hypnosis is Real.
The BBC has reported research from Hull University that used brain
scans to detect the effects of hypnosis on the brain.
http://blog.trance-formations.com/2009/11/brain-scans-show-that-hypnosis-is-real.html
Hypnosis Motivation Institute
Sports Performance - Hypnosis Strikes Gold for Amateur, Olympic,
and Pro Athletes.
http//www.hypnosis.edu/articles/sports/performance/