What if someone has had heart surgery in the past and has now fully recovered and plans to visit USA on visitor visa. So any issues relating to heart going forward are considered to be pre existing?
Also, I read some place that Cancer is considered pre-existing even though it might not have been diagnosed earlier or prior to the visit to USA, since cancer doesnt occur over night. So basically with that logic heat conditions dont occur overnight too. These all build up with time. So what is really pre-existing?