Mind filled with aggression,revenge,negative thoughts,envy can be termed as a disease mind.What you think you become.If your mind is free from all worries you are fit and sooner or later will be on the top of the world.A disease mind is more dangerous than the disease itself because for a disease there is cure and there is no cure or medicine for a disease mind. Nobody can change your state of mind expect you.The cure/change for the disease mind is within oneself (which is difficult but not impossible) whereas the cure for a disease depends on external factors like doctor, medicines,sophisticated medical equipments which is available directly.