I once read of a guy who had a large, terminal brain tumor and didn't know until he only had one month to live. He fainted one day outside and that's when he was diagnosed. He said his only symptoms were the occasional headache but somehow I doubt he was saying the whole story. He had to have had other issues, right? Or the headaches must have been abnomal.. Oh well.
Realistically I doubt I have a tumor but hypochondria is irrational. I KNOW I'm fine but I feel my brain will never be at rest 100% until I get a MRI or two.