Reiki is a Japanese technique for stress reduction and relaxation that also promotes healing. 

It is spiritually guided life force energy which is administered by "laying on hands" If one's "life force energy" is low, then we are more likely to get sick or feel stress.  

Reiki energy has several basic effects: it brings about deep relaxation, destroys energy blockages and increases the vibrational  frequency of the body.  Reiki seeks to restore order to the body whose vital energy has become unbalanced.