Hypnosis is a mental state associated with increased suggestibility, altered sensory perception, and a measurable shift in use of functional centers of the brain. As discussed in the neuroscience section, peer reviewed research studies have shown that hypnotized subjects exhibit both altered fMRI scans, and measurable perceptional abilities that cannot be reproduced in subjects not under hypnotic trance.
Many studies have shown that hypnosis is effective for the treatment of pain and anxiety, promoting weight loss, and helping people quit smoking.