The disorder may be associated with Addison's disease, atherosclerosis (build-up of fatty deposits in the arteries), diabetes, pheochromocytoma, porphyria, and certain neurological disorders, including autoimmune autonomic ganglionopathy, multiple system atrophy and other forms of dysautonomia. It is also associated with Ehlers–Danlos syndrome and anorexia nervosa. It is also present in many patients with Parkinson's disease or Lewy body dementia resulting from sympathetic denervation of the heart or as a side-effect of dopaminomimetic therapy. This rarely leads to fainting unless the person has developed true autonomic failure or has an unrelated heart problem.