When insurance companies refer to pre-existing conditions what they are talking about is any serious, irreversible and/or terminal illness that won't go away and will cost them hundreds of thousands of dollars increasing toward the end of the insured's life. Examples include Advanced Emphyseyma/COPD, Major Cancers, Viral Cardiomyopathy, Massive heart damage or having been installed a pacemaker, AIDS, viral menengitis, Type A Diabetes, cirrhosis of the liver, or Acute Asthma in patients older than age 65. Almost any type of serious brain abnormality such as an AVM, Chronic Brain Tumors regardlesss if it is mallignant, benign, or terminated will almost always constitute a pre-existing condition, naturally.