Hypnosis has been used as a therapeutical tool for centuries, but only in the past 50 years have the clinical applications been delineated. As evident in the medical literature, the use of hypnosis and hypnotherapy by the medical community has increased, partly as result of a growing awareness of hypnotherapy as an available treatment modality, and also as a result of major improvements in research methodology through strict standardization. Hypnotherapy, once considered to be limited to entertainment, has now proven useful in the treatment of a wide variety of medical and psychological illnesses.