Mesmer's original interest was in the effect of celestial bodies on human lives. He later became interested in the effects of magnetism, and found that magnets could have tremendous healing effects on the human body. Mesmer believed that the human body contained a magnetic fluid that promoted health and well being. It was thought that any blockage to the normal flow of this magnetic fluid would result in illness, and that the use of the mesmerism technique could restore the normal flow.

The central theoretical disagreement regarding hypnosis is known as the "state versus nonstate" debate. When Braid introduced the concept of hypnotism, he equivocated over the nature of the "state", sometimes describing it as a specific sleep-like neurological state comparable to animal hibernation or yogic meditation, while at other times he emphasised that hypnotism encompasses a number of different stages or states that are an extension of ordinary psychological and physiological processes. Overall, Braid appears to have moved from a more "special state" understanding of hypnotism toward a more complex "nonstate" orientation.[citation needed]

In the 2000s, hypnotherapists began to combine aspects of solution-focused brief therapy (SFBT) with Ericksonian hypnotherapy to produce therapy that was goal focused (what the client wanted to achieve) rather than the more traditional problem focused approach (spending time discussing the issues that brought the client to seek help). A solution-focused hypnotherapy session may include techniques from NLP.[13]
Neuro-Linguistic Programming (NLP) is the name given to a series of models and techniques used to enhance the therapist's ability to do hypnotherapy. NLP consists of a number of models, with a series of techniques based on those models. Sensory acuity and physiology is one model whose premise is that a person's thought processes change their physiological state. People recognize such a physiological change when startled. The body receives a great dose of adrenaline, the heart beats faster, the scare may be verbalized by shouting, and the startled person may sweat. Sensory acuity, (i.e., being attuned to changes occurring in another person) will strengthen communication to a person in ways over and above simple verbal cues, therefore making the therapist more effective. A second model of NLP deals with representational systems. The idea behind this model is that different people represent knowledge in different sensory styles. In other words, an individual's language reveals that person's mode of representation. There are three basic modes of representation. These are: Auditory, Visual, and Kinesthetic. The same information will be expressed differently by each. For example, the auditory person might say, "That sounds good to me;" the visual person might convey, "I see it the same way;" and the kinesthetic person would offer, "I'm comfortable with it too."

Stand or sit face-to-face. Look into the eyes of the person. Have the person place their hand on top of yours palm to palm. Tell your subject to continue to look into your eyes until you tell them to stop. Pause and tell the subject that you will count to three and that on three they need to press down on your hand and that you will press up against theirs. Explain that what they feel is your energy. Then command them to listen to your instructions.
Suggestion therapy relies on the patient’s ability to respond to suggestions from the hypnotherapist while in this trance-like state. This method is commonly used to control or stop unwanted behaviors such as smoking, gambling, nail biting, or over-eating. It has also been shown particularly useful in treating pain, or increasing the instance of positive behavior such as self-motivation or confidence.
This state of awareness can be achieved by relaxing the body, focusing on breathing, and shifting attention away from the external environment. In this state, the patient has a heightened receptivity to suggestion. The usual procedure for inducing a hypnotic trance in another person is by direct command repeated in a soothing, monotonous tone of voice.
Austrian physician, Franz Mesmer (1734–1815), is credited with being the first person to scientifically investigate the idea of hypnotherapy, in 1779, to treat a variety of health conditions. Mesmer studied medicine at the University of Vienna and received his medical degree in 1766. Mesmer is believed to have been the first doctor to understand the relationship of psychological trauma to illness. He induced a trance-like state, which became known as mesmerism, in his patients to successfully treat nervous disorders. These techniques became the foundation for modern-day hypnotherapy.
Placing persons in a drowsy, sleeplike state in which they allegedly become vulnerable to the suggestions made by the hypnotist. Hypnosis may also be used to tap into the unconscious and is often characterized by vivid recall of memories and fantasies. These properties make hypnosis a useful tool in psychotherapy. Hypnosis also has sinister implications, for subjects may be manipulated to perform embarrassing actions or be susceptible to carrying out the hypnotist's commands after the hypnosis session (posthypnotic suggestion).
Cally Stewart, OTD, OTR/L, CH joined the Center for Healthy Living in January 2017.  She was certified in hypnotherapy in 2009 and has practiced in a variety of health care settings including cancer care, family medicine, rehabilitation from injury or surgery, and chronic disease self-management.  Cally has a B.A. in psychology from Washington University in St. Louis, Missouri.  She received her master's and doctorate in occupational therapy at Tufts University and is a licensed occupational therapist in Massachusetts.  She also holds a certification in hypnotherapy through the International Association of Counselors and Therapists. 
Contemporary hypnotism uses a variety of suggestion forms including direct verbal suggestions, "indirect" verbal suggestions such as requests or insinuations, metaphors and other rhetorical figures of speech, and non-verbal suggestion in the form of mental imagery, voice tonality, and physical manipulation. A distinction is commonly made between suggestions delivered "permissively" and those delivered in a more "authoritarian" manner. Harvard hypnotherapist Deirdre Barrett writes that most modern research suggestions are designed to bring about immediate responses, whereas hypnotherapeutic suggestions are usually post-hypnotic ones that are intended to trigger responses affecting behaviour for periods ranging from days to a lifetime in duration. The hypnotherapeutic ones are often repeated in multiple sessions before they achieve peak effectiveness.[39]

Mesmer developed a general theory of disease he called “animal magnetism,” which held that every living thing carries within it an internal magnetic force, in liquid form. Illness arises when this fluid becomes blocked, and can be cured if it can be coaxed to flow again, or so Mesmer’s thinking went. To get that fluid flowing, as science journalist Jo Marchant describes in her recent book, Cure, Mesmer “simply waved his hands to direct it through his patients’ bodies” — the origin of those melodramatic hand motions that stage hypnotists use today.”
Hypnosis is first and foremost a self-accepted journey away from the reality of the moment. Although the trance state is often referred to as if the patient is asleep, nothing could be further from the truth. The patient is fully awake at all times. The hypnotic subject is simply in a heightened, more receptive state of mind. This fact is proven with inductions called open-eye techniques, where the patient keeps his/her eyes open during the hypnotherapy. Full and deep trance is still achievable.
Hypnotherapy is a form of therapy used to reprogram the subconscious mind. When under hypnosis, you put your mind and body into a heightened state of learning, making you more susceptible to suggestions for self-improvement or behavior modification. The goal is to put the subconscious and conscious mind in harmony, which in turn helps give you greater control over your behavior and emotions.
In 2007, a meta-analysis from the Cochrane Collaboration found that the therapeutic effect of hypnotherapy was "superior to that of a waiting list control or usual medical management, for abdominal pain and composite primary IBS symptoms, in the short term in patients who fail standard medical therapy", with no harmful side-effects. However the authors noted that the quality of data available was inadequate to draw any firm conclusions.[2]