The Japanese word Reiki is derived from rei ("universal") and ki ('life energy"). The ancient Reiki healing practices of Tibetan Buddhism were believed to have been lost over the centuries, until Dr. Usui rediscovered and reinterpreted them in the late 19th century. One of his pupils, Dr. Chujiro Hayashi, passed on this knowledge to Hawaio Takata, a Japanese woman living in Hawaii, who introduced reiki in the West in the 1970s. In 1981, her pupils formed the Reiki Alliance, which now has over 800 members worldwide.

The principles on which Reiki is based lie far beyond the realm of conventional science, and most doctors would regard it as little more than an exotic-sounding healing ritual. While the concepts and terminology may seem far-fetched, some doctors might see reiki as an artistic and imaginative adjunct to health care, provided that the physical disease is being dealt with by conventional treatment.