Hello. How can someone know that its brain tumor? My age is 19 (mobile) I am facing this problem from really long (7-8 years) whenever I sit for few minutes 10-15 doing something on phone or whatever and after few minutes when I get up I suddenly fell like weakness but weakness from mind I feel like dizziness every time especially whenever I got up from using my phone I never had any treatment for that and yes I do not smoke never consumed alcohol what reports makes sure that its or its?nt brain tumor thank you.