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. It may last minutes to hours and can fade, but the real bleed often follows within days. When the aneurysm ruptures, the headache is explosive, instantaneous, and paired with nausea, vomiting, and stiff neck. Light hurts, you may faint or seize, and any movement makes the pain worse. Quick medical care is critical; call 911 if you or someone around you develops this thunder-clap headache.
| Stage | Common Signs |
|---|---|
| Silent | No symptoms, found by chance on scan |
| Pressure effect | Daily dull headache, droopy lid, double vision, eye pain |
| Warning leak | Sudden severe headache that peaks in seconds, may clear |
| Rupture | Explosive worst-ever headache, vomiting, stiff neck, light bother, faint/seizure |