I know someone that after awhile that they are really close to that person.. starts to mimic the other persons illness, rather it's chronic pain, or emotional health issues. After asking and prodding the symptoms weeks later.. the person feels they also have that illness and somehow develop all the symptoms. I don't know if the person realizes they are doing it... or if it's Hypochondria and they actually believe it? However, whomever they are close to.. they start to develop the same illness they have.