Yes, you are definitely right there is an exceptionally strong link between the emotional and physical self. I do not know much about Reiki, but I use Spring Forest Qigong which focusses on releasing blocked energies as well. I am finding that my multiple chemical sensitivies are getting better. If you don't know about MCS, it is very debilitating. The immune system and cental nervous system is "out of whack".
Qigong is positively affecting my overall sense of well-being and therefore my immune system. My outlook on life has improved tremendously. At the moment, I have MCS and systemic candida, yet I am feeling mentally and spiritually better than I ever have in my life!! My physical body and therefore the candida I believe will naturally follow the healing of the mind and spirit (with the help of the things I mentioned such as cleansing...). I should mention that I have also kept a dairy to get rid of some bad feelings.
Shelley and Jhan advocate the mind/body connection as well.