Reiki is a healing practice that originated in Japan; it is part of complementary and alternative medicine (CAM).
It is based on the idea that there is a universal (or source) energy that supports the body's innate healing abilities. Practitioners seek to access this energy, allowing it to flow to the body and facilitate healing.

In a Reiki session, the client lies down or sits comfortably, fully clothed. The practitioner's hands are placed lightly on or just above the client's body, palms down, using a series of 12 to 15 different hand positions. Each position is held for about 2 to 5 minutes, or until the practitioner feels that the flow of energy — experienced as sensations, such as heat or tingling in the hands — has slowed or stopped.
The number of sessions depends on the health needs of the client. Typically, the practitioner delivers at least 4 sessions of 30 to 90 minutes each. The duration of sessions may be shorter in certain health care settings.

National Instututes of Health. National Center for Complementary and Alternative Medicine. Reiki information. Internet. Accessed on November 1, 2009.