Brain cancer can start in the brain or travel there from elsewhere. Signs depend on where the tumor sits and how fast it grows. Headache is the symptom people mention most. It often starts dull, wakes you at night, and feels worse when you bend over or cough. Nausea and vomiting may show up with the headache, especially in the morning. The sick feeling can fade after you throw up, then return later. Vision changes. You might see double, lose the outer edges of sight, or notice flashing lights even when your eyes are closed. Weakness or numbness creeps in.... Learn more