Hypnosis is often thought to be a wakeful state of focused attention and heightened suggestibility, with diminished peripheral awareness.

According to the American Psychological Association's Division 30, hypnosis may bring about "...changes in subjective experience, alterations in perception, sensation, emotion, thought or behavior." The hypnotic state may also facilitate change in the body: it has been successfully used as a treatment for irritable bowel syndrome, as an alternative to chemical anaesthesia, and it has been studied as a way to soothe skin ailments.

Skeptics point out the difficulty distinguishing between hypnosis and the placebo effect, proposing that the state called hypnosis is

"so heavily reliant upon the effects of suggestion and belief that it would be hard to imagine how a credible placebo control could ever be devised for a hypnotism study."

Self-hypnosis is popularly used by people who want to quit smoking and reduce stress, while stage hypnosis can be used to persuade people to perform unusual public feats.

Franz Mesmer in the 1700's believed that there was a magnetic fluid that surrounds the body. He experimented with magnets to influence this field and so cause healing. He later found that the same effects could be created by waving the hands in front of someone's face. Although his theories were later discredited, the effects he was able to achieve with subjects may shed light on modern day hypnosis. Franz Mesmer is where the word mesmerize originated.

The word 'hypnosis' itself is the invention of 19th century Scottish physician James Braid.

Uses of hypnosis

Hypnosis has been studied in many clinical situations with varying degrees of success. It has been used as a painkiller, an adjunct to weight loss, a treatment of skin disease, and a way to soothe anxious surgical patients. It has also been used as part of psychological therapy, a method of habit control, a way to relax, and a tool to enhance sports performance.

Physical applications

A large number of clinical studies show that hypnosis can reduce the pain experienced by people undergoing burn-wound debridement, bone marrow aspirations, and childbirth. The International Journal of Clinical and Experimental Hypnosis found that hypnosis relieved the pain of 75% of 933 subjects participating in 27 different experiments.Nash, Michael R. "The Truth and the Hype of Hypnosis". Scientific American: July 2001

In 1996, the National Institutes of Health declared hypnosis effective in reducing pain from cancer and other chronic conditions. Nausea and other symptoms related to incurable diseases may also be controlled with hypnosis. For example, research done at the Mt. Sinai School of Medicine studied two groups of patients facing surgery for breast cancer. The group that received hypnosis reported less pain, nausea, and anxiety post-surgery. There was a cost benefit as well: the average hypnosis patient reduced the cost of treatment by an average of $772.00.