Hypnotherapy has been used to stop self-destructive and addictive habits like smoking. It has also been used to curb the urge to eat for overeaters, to stem the disruptive actions of tics, cure insomnia , stop bed-wetting, and minimize anxiety. Excessive stress can be generated from any number of sources and can be the springboard for anxiety. Some of the more prominent sources of anxiety and stress for which people seek hypnotherapy are: public speaking, test taking, and job stress. Hypnotherapy also works well for other anxiety disorders such as phobias and has proven to be an effective treatment for mild to moderate depression. In one study, hypnotherapy was used in conjunction with traditional cognitive therapy, to assist persons who had severe aversion to needles. The treatment was necessary, because it was essential that each participant receive periodic medical injections. However, the participants would have become non-compliant without the adjunct intervention of hypnotherapy. In another case, involving care for terminally ill cancer patients, it was concluded that hypnotherapy was more effective at enhancing quality of life and relieving anxiety and depressive symptoms, when compared to others who received traditional care.
Hypnosis, when using proven therapeutic procedures, can be a highly effective form of treatment for many mental, psychosomatic, and physical disorders. For example, through the use of regressive techniques, an adult patient may mentally voyage back to a point in youth that was particularly troublesome, allowing the healing of old emotional wounds. Another patient can be led to understand that emotional pain has been converted to physical pain, and that the pain can be eliminated once the source has been addressed. Or, a person suffering from chronic pain can be taught to control the pain without use of medications. There are a number of techniques for correcting dysfunctional behaviors such as self-destructive habits, anxiety disorders, and even managing side effects of various medical treatments and procedures.

Some hypnotists view suggestion as a form of communication that is directed primarily to the subject's conscious mind,[40] whereas others view it as a means of communicating with the "unconscious" or "subconscious" mind.[40][41] These concepts were introduced into hypnotism at the end of the 19th century by Sigmund Freud and Pierre Janet. Sigmund Freud's psychoanalytic theory describes conscious thoughts as being at the surface of the mind and unconscious processes as being deeper in the mind.[42] Braid, Bernheim, and other Victorian pioneers of hypnotism did not refer to the unconscious mind but saw hypnotic suggestions as being addressed to the subject's conscious mind. Indeed, Braid actually defines hypnotism as focused (conscious) attention upon a dominant idea (or suggestion). Different views regarding the nature of the mind have led to different conceptions of suggestion. Hypnotists who believe that responses are mediated primarily by an "unconscious mind", like Milton Erickson, make use of indirect suggestions such as metaphors or stories whose intended meaning may be concealed from the subject's conscious mind. The concept of subliminal suggestion depends upon this view of the mind. By contrast, hypnotists who believe that responses to suggestion are primarily mediated by the conscious mind, such as Theodore Barber and Nicholas Spanos, have tended to make more use of direct verbal suggestions and instructions.[citation needed]
Although he rejected the transcendental/metaphysical interpretation given to these phenomena outright, Braid accepted that these accounts of Oriental practices supported his view that the effects of hypnotism could be produced in solitude, without the presence of any other person (as he had already proved to his own satisfaction with the experiments he had conducted in November 1841); and he saw correlations between many of the "metaphysical" Oriental practices and his own "rational" neuro-hypnotism, and totally rejected all of the fluid theories and magnetic practices of the mesmerists. As he later wrote:
“Before attending the Hypnotherapy Academy of America, I had already had over 500 hours of hypnotherapy training; however, I felt that I was missing some important concepts and skills, so I went to the Academy hoping to get what I was unable to get from other training. My goals were completely fulfilled. I received a solid foundation in hypnosis and hypnotherapy and learned how to take hypnotherapy to new heights and greater depths. As a result of the Academy training, I now do hypnotic work more efficiently and more effectively than with my prior training. Because the quality of my work as a hypnotherapist has significantly improved through the Academy training, I can offer greater value to my patients, and I can more easily market my practice.
Modern hypnotherapy is widely accepted for the treatment of certain habit disorders, to control irrational fears,[35][36] as well as in the treatment of conditions such as insomnia[37] and addiction.[38] Hypnosis has also been used to enhance recovery from non-psychological conditions such as after surgical procedures,[39] in breast cancer care[40] and even with gastro-intestinal problems,[41] including IBS.[42][43]
State theorists interpret the effects of hypnotism as due primarily to a specific, abnormal, and uniform psychological or physiological state of some description, often referred to as "hypnotic trance" or an "altered state of consciousness". Nonstate theorists rejected the idea of hypnotic trance and interpret the effects of hypnotism as due to a combination of multiple task-specific factors derived from normal cognitive, behavioural, and social psychology, such as social role-perception and favorable motivation (Sarbin), active imagination and positive cognitive set (Barber), response expectancy (Kirsch), and the active use of task-specific subjective strategies (Spanos). The personality psychologist Robert White is often cited as providing one of the first nonstate definitions of hypnosis in a 1941 article:
The first neuropsychological theory of hypnotic suggestion was introduced early by James Braid who adopted his friend and colleague William Carpenter's theory of the ideo-motor reflex response to account for the phenomenon of hypnotism. Carpenter had observed from close examination of everyday experience that, under certain circumstances, the mere idea of a muscular movement could be sufficient to produce a reflexive, or automatic, contraction or movement of the muscles involved, albeit in a very small degree. Braid extended Carpenter's theory to encompass the observation that a wide variety of bodily responses besides muscular movement can be thus affected, for example, the idea of sucking a lemon can automatically stimulate salivation, a secretory response. Braid, therefore, adopted the term "ideo-dynamic", meaning "by the power of an idea", to explain a broad range of "psycho-physiological" (mind–body) phenomena. Braid coined the term "mono-ideodynamic" to refer to the theory that hypnotism operates by concentrating attention on a single idea in order to amplify the ideo-dynamic reflex response. Variations of the basic ideo-motor, or ideo-dynamic, theory of suggestion have continued to exercise considerable influence over subsequent theories of hypnosis, including those of Clark L. Hull, Hans Eysenck, and Ernest Rossi.[40] It should be noted that in Victorian psychology the word "idea" encompasses any mental representation, including mental imagery, memories, etc.
Although most practitioners receive their training in hypnotherapy or relaxation as a part of their academic training, the American Society of Clinical Hypnosis and the Society for Clinical and Experimental Hypnosis maintain training programs as well as a registry of practitioners (see previous box). Training in teaching relaxation techniques is provided through various routes from self-teaching and apprenticeships to a number of short courses. Many yoga centers also teach relaxation and offer courses to train yoga teachers.​teachers.
Hypnosis is not a psychotherapeutic treatment or a form of psychotherapy, but rather a tool or procedure that helps facilitate various types of therapies and medical or psychological treatments. Only trained health care providers certified in clinical hypnosis can decide, with their patient, if hypnosis should be used along with other treatments. As with psychotherapy, the length of hypnosis treatment varies, depending on the complexity of the problem.