A reiki treatment in progress

Reiki is a [-[spiritual practice]]^[1] developed in 1922 by Mikao Usui. After three weeks of fasting and meditating on Mount Kurama, in Japan, Usui claimed to receive the ability of "healing without energy depletion".^[2] A portion of the practice, tenohira or palm healing, is used as a form of complementary and alternative medicine (CAM).^[3][4] Tenohira is a technique whereby practitioners believe they are moving "healing energy" (a form of ki) through the palms.^[5][6]

There is no generally accepted scientific evidence for either the existence of ki or any mechanism for its manipulation, and a systematic review of randomized clinical trials conducted in 2008 did not support the efficacy of reiki or its recommendation for use in the treatment of any condition.^[7][8]