Reiki (靈氣, 霊気, or レイキ) is a technique of alternative medicine, developed (or rediscovered) during the latter half of the 19th century by Mikao Usui in Japan. It first gained widespread popularity outside Japan, particularly in Europe and the U.S.
The name Reiki comes from the Japanese rei (霊, presently meaning spirit/soul, it had an older meaning of posessed shamaness) and ki (気, energy/life energy, see chi or qi). From this, a verb may also be derived. Other common definitions are "universal life force energy" or "healing energy of the universe".
Practitioners believe that they are able to direct Reiki energy, which flows from the universe through their bodies and from the palms of their hands, to specific parts of their own or others' bodies, in order to facilitate healing. Many scientists dispute the effectiveness of Reiki, claiming that Reiki energy cannot be measured by any known observational technique. There is no conclusive scientific evidence of positive results from this form of therapy.
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