A brain aneurysm is a weak spot in an artery wall that balloons outward. Most live quietly for years, but when one leaks or bursts it becomes a medical emergency. Knowing the warning signs can save your life. Un-ruptured aneurysms usually cause no symptoms at all. If the sac pushes on nearby nerves you may notice new daily headaches, a droopy eyelid, double vision, or pain behind the eye. These clues are easy to blame on fatigue or allergies, so they’re often missed. A leak typically starts with a sudden, severe headache—patients call it the worst headache of their life.... Learn more