Brain tumors can cause various signs and symptoms like personality changes, confusion, vomiting, nausea, prolonged fatigue, seizures, impaired vision, bad speech and hearing, and progressive headaches. They are the leading cause of solid cancer death in children under 20. Some common types include gliomas, choroid plexus tumors, embryonal tumors, germ cell tumors, pineal tumors, and meningiomas. Risk factors include inherited conditions, age, chemical exposure, radiation, and metastasis from other cancers. Diagnosis involves a neurological examination, head CT scan, brain MRI, and PET scan of the brain.