Reiki is a Japanese healing practice that combines the concepts of universal life energy ("rei") and life energy ("kei"). It is based on the idea that all living things are surrounded by and composed of energy. Reiki focuses on mind-body-spirit unity and the connection between all things. It is intended as a complementary therapy to support conventional medicine, not as a replacement. Reiki works by balancing energies to stimulate the body's natural healing abilities, emphasizing the spiritual and mind-body connection rather than directly treating specific health conditions.