My son is 11 since he was like 3 he has been having random nose bleed and migrains, he also grinds his teeth is this a sign of a brain tumor? am concerned as i have had thyroid cancer.

Children : Children grinding their teeth is quite normal and not indicative of a tumor in and of itself. You should see his pediatrician regarding the random nosebleeds and migranes.

Not likely: Nose bleeds and migraines are vascular issues most likely. Tooth grinding can be a sign of anxiety and/or a bad bite. But let's get your son examined by a physicians and a dentist to get an accurate diagnosis so his problems can be treated.