Reiki is used worldwide as a spiritual-energetic healing method. During a treatment, a space is created in which the energy of Reiki is clearly present. This happens through gentle touch, or even without touch. This energy reminds the client of his/her/their spiritual essence and the enormous self-healing capacity which he/she/they naturally possess(es). Although the underlying mechanism of Reiki cannot be fully scientifically explained yet, its effects can be clearly felt (and measured). Even people who are not that familiar with terms as energy and spirituality, experience Reiki as clearly observable and beneficial. Positive treatment results contribute to the growing application of and research into Reiki as a complementary therapy, also in a medical contexts.