Many operators manual techniques of chinese medicine and other techniques of the far east have been the Gua Sha because it is taught as a "technical companion" in courses of Tuina or Shiatsu massage, but few use it in the treatments and are rare medical acupuncturists who integrate it in their work. It is likely that the lower spread of the Gua Sha depends on the fact that the operators have only had one training summary, with a dexterity too little exercised, or do not feel they are fully aware of the entire process. The text of Arya Nielsen, only in Italian to illustrate this ancient technique, therefore, has a considerable importance, especially in Italy, the place in which these disciplines and skills are currently not recognized by legislation that protects workers too, and indeed are viewed with suspicion, skepticism, and misconceptions. The research work carried out by the author on the main database of studies in which is used in Gua Sha, the systematization and classification of the same, allows the reader to understand how this technique has been experimented and studied in China and in the west, and what are the major areas of application and success. Very important is the chapter on the physiological mechanisms of Gua Sha and on studies that highlight the dynamics of the effects induced by the use of the technique in the eyes of western medicine.