There has been different studies about how Reiki and energy work has been proven to be helpful medically. See below for links to different articles.
Herbert Irving Comprehensive Cancer Center is one of the first to include western techniques with natural and holistic Options. They see the importance of supplying services like Reiki, nutrition, yoga (among others) in addition to Chemotherapy, radiation and surgery.
Reiki Eases Burnout Syndrome “A study involving health care professionals diagnosed with burnout syndrome showed that those who receive a single session of Reiki experienced increased heart rate variability and body temperature, supporting the researchers’ hypothesis that Reiki has an effect on the parasympathetic nervous system.”