Hypnotherapy is a psychotherapy wherein the patient is hypnotized such that the subconscious mind is open to information that can alter behavior such as smoking, reduce anxiety, control weight problems, or release trauma causing fear and phobias. Historically hypnotherapy was used prior to surgery to reduce fear and anxiety. Guided imagery as well as hypnotherapy are very common forms of therapies used prior to surgeries to reduce stress and in some cases hypnotherapy is used as anesthesia.