These are physical disorders that are caused by or notably influenced by emotional factors, they are also termed functional illness.
We now know from a plethora of research that the communication between the bodies organs and the central nervous system (the brain and spinal cord) is a two way process. There are many neurones around the heart that send messages to the brain and likewise in the gut.
Certain skin conditions and gastrointestinal problems particularly IBS (irritable bowel syndrome) are really influenced by your emotional state.
The condition then further affects the emotional state and a vicious cycle develops. Hypnotherapy, guided visualisation techniques and home exercises have been clinically shown to have very positive effects on bringing these conditions and many others under your control.