In an average the lifespan of medical doctors is 58.5 years, the lifespan of the ordinary people is 75 years. I measured the human nonlinear electromagnetic field (NEMF) for almost 40 years, that is why I know that the diseases first appear in NEMF and it takes a long time until they manifest themselves in the physical body with all their symptoms. This article offers explanation based on our measurements of the human nonlinear electromagnetic field (NEMF) that our medical doctors have short lifespan because they deal with sick people all the time.