Hypnosis is a procedure during which a health professional or researcher suggests that a client, patient, or subject experience changes in sensations, perceptions, thoughts, or behavior. The hypnotic context is generally established by an induction procedure. Although there are many hypnotic inductions, most include suggestions for relaxation, calmness and well-being. Instructions to imagine or think about pleasant experiences are also commonly included in hypnotic inductions. People respond to hypnosis in different ways. Some describe their experience as an altered state of consciousness. Others describe hypnosis as a normal state of focused attention, in which they feel very calm and relaxed. Regardless of how and to what degree they respond, most people describe the experience as very pleasant.

Some people are very responsive to hypnotic suggestions and others are less responsive. A person's ability to experience hypnotic suggestions can be inhibited by fears and concerns arising from some common misconceptions. Contrary to some depictions of hypnosis books, movies or on television, people who have been hypnotized do not lose control over their behavior. They typically remain aware or who they are and where they are, and unless amnesia has been specifically suggested, they usually remember what transpired during hypnosis. Hypnosis makes it easier for people to experience suggestions, but it does not force them to have these experiences.

Hypnosis is not a type of therapy, like psychoanalysis or behavior therapy. Instead, it is a procedure the can be used to facilitate therapy. Because it is not a treatment in and of itself, training in hypnosis is not sufficient for the conducted therapy. Clinical hypnosis should be used only by properly trained and credentialed health care professionals (e.g., licensed clinical psychologists), who have also been trained in the clinical use of hypnosis and are working within the area of their professional expertise.

Hypnosis has been used in the treatment of pain, depression, anxiety, stress, habit disorders, and many other psychological and medical problems. However, it may not be useful for all psychological problems or for all patients or clients. The decision to use hypnosis as an adjunct to treatment can only be made in consultation with a qualified health care provider who has been trained in the use of limitations of clinical hypnosis. In addition to its use in clinical settings, hypnosis is used in research, with the goal of learning more about the nature of hypnosis itself, as well as its impact on sensation, perception, learning, memory, and physiology. Researchers also study the value of hypnosis in the treatment of physical and psychological problems.

(This definition and description of hypnosis was prepared by the Executive Committee of American Psychological Association, Division of Psychology Hypnosis. Permission to reproduce this document is freely granted)