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.
More than 200 years later, research in neuroscience is confirming at least parts of Mesmer’s outlandish theory. No, there is not magnetic fluid coursing through our bodies. But the power of mere suggestion — of imagination, as Franklin phrased it — is a more effective treatment than many modern skeptics might expect, causing real, measurable changes in the body and brain. Hypnotism has been shown to be an effective treatment for psychological problems, like phobias and eating disorders, but the practice also helps people with physical problems, including pain — both acute and chronic — and some gastrointestinal diseases. Physicians and psychologists have observed this with their own eyes for decades; now, many of them say that brain-imaging studies (not to mention the deep respect people tend to have for all things prefixed by “neuro”) are helping them finally prove their point.
Systems theory, in this context, may be regarded as an extension of Braid's original conceptualization of hypnosis as involving "the brain and nervous system generally".[74](p31) Systems theory considers the nervous system's organization into interacting subsystems. Hypnotic phenomena thus involve not only increased or decreased activity of particular subsystems, but also their interaction. A central phenomenon in this regard is that of feedback loops, which suggest a mechanism for creating hypnotic phenomena.[183]

Could imbalance in the autonomic nervous system explain the complexity and heterogeneity of autism spectrum disorder (ASD)? Could teaching kids and families affected by ASD skills in autonomic regulation broadly improve comfort and functioning? This is the first of three blog posts on our work at the Center for Applied Psychophysiology and Self-regulation at RIT.

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.

Sometimes those shoulds and shouldn'ts seem to only take us so far, before we reach a seemingly insurmountable hurdle that even the strongest willpower just can't quite conquer. This is because we're trying to address these issues on a purely conscious level, which is similar to applying a bandaid over an internal wound. Sooner or later, we need to deal with the root cause.
Whereas the older "depth scales" tried to infer the level of "hypnotic trance" from supposed observable signs such as spontaneous amnesia, most subsequent scales have measured the degree of observed or self-evaluated responsiveness to specific suggestion tests such as direct suggestions of arm rigidity (catalepsy). The Stanford, Harvard, HIP, and most other susceptibility scales convert numbers into an assessment of a person's susceptibility as "high", "medium", or "low". Approximately 80% of the population are medium, 10% are high, and 10% are low. There is some controversy as to whether this is distributed on a "normal" bell-shaped curve or whether it is bi-modal with a small "blip" of people at the high end.[45] Hypnotizability Scores are highly stable over a person's lifetime. Research by Deirdre Barrett has found that there are two distinct types of highly susceptible subjects, which she terms fantasizers and dissociaters. Fantasizers score high on absorption scales, find it easy to block out real-world stimuli without hypnosis, spend much time daydreaming, report imaginary companions as a child, and grew up with parents who encouraged imaginary play. Dissociaters often have a history of childhood abuse or other trauma, learned to escape into numbness, and to forget unpleasant events. Their association to "daydreaming" was often going blank rather than creating vividly recalled fantasies. Both score equally high on formal scales of hypnotic susceptibility.[46][47][48]
Hypnotherapy is used in a number of fields including psychotherapy, surgery, dentistry, research, and medicine. Hypnotherapy is commonly used as an alternative treatment for a wide range of health conditions, including weight control, pain management, and smoking cessation. It is also used to control pain in a variety of conditions such as headache, facial neuralgia, arthritis, burns, musculoskeletal disorders, childbirth, and many more. Hypnotherapy is being used in place of anesthesia, particularly in patients who prove to be allergic to anesthetic drugs, for surgeries such as hysterectomies, cesarean sections, certain cardiovascular procedures, thyroidectomy, and others. Dentistry is using hypnotherapy with success on patients who are allergic to all types of novocaine drugs. Hypnotherapy is also useful in helping patients overcome phobias.
Around 1900, there were very few preoperative anesthetic drugs available. Patients were naturally apprehensive when facing surgery. One out of four hundred patients would die, not from the surgical procedure, but from the anesthesia. Dr. Henry Munro was one of the first physicians to use hypnotherapy to alleviate patient fears about having surgery. He would get his patients into a hypnotic state and discuss their fears with them, telling them they would feel a lot better following surgery. Ether was the most common anesthetic at that time, and Dr. Munro found that he was able to perform surgery using only about 10% of the usual amount of ether.
"We have 3 hypnotists in our office, so we can help almost anyone. Our clients almost always come to us because they feel "blocked" by something inside. Something prevents them from moving forward, and they don't know what it is. We show them in the first session exactly what the brand new fMRI research shows is stopping them from change and how we will overcome it with hypnosis. Stress, fears, sleep problems, chronic pain, sexual problems, depression, bad habits, addictions, all result from the fact that our subconscious mind is out of tune with our conscious desires. Hypnotism is uniquely qualified to address that."

You are getting very sleepy.... While hypnosis is often associated with sideshow performances, it's not a magical act. Rather, it’s a technique for putting someone into a state of heightened concentration where they are more suggestible. Therapists use hypnosis (also referred to as hypnotherapy or hypnotic suggestion) to help patients break bad habits, such as smoking, or achieve some other positive change, like losing weight. They accomplish this with the help of mental imagery and soothing verbal repetition that eases the patient into a trance-like state; once relaxed, patients’ minds are more open to transformative messages. Hypnosis can also help people cope with negative emotional states, like stress and anxiety, as well as pain, fatigue, insomnia, mood disorders, and more. In rare cases where patients are resistant to hypnoses, alternative therapies may be used.  

Children and adolescents are really good at learning to control their psychophysiological processes because that's the business they're in. Self-regulating our own physiology, emotion and cognition is often more powerful than externally applied therapies. It is time to revolutionize health and care by balancing skills with pills -- helping children change their minds.
The Federal Dictionary of Occupational Titles describes the job of the hypnotherapist: "Induces hypnotic state in client to increase motivation or alter behavior patterns: Consults with client to determine nature of problem. Prepares client to enter hypnotic state by explaining how hypnosis works and what client will experience. Tests subject to determine degree of physical and emotional suggestibility. Induces hypnotic state in client, using individualized methods and techniques of hypnosis based on interpretation of test results and analysis of client's problem. May train client in self-hypnosis conditioning. GOE: 10.02.02 STRENGTH: S GED: R4 M3 L4 SVP: 7 DLU: 77"[8]