Requires a medical diagnosisAn unruptured aneurysm usually causes no symptoms. A key symptom of a ruptured aneurysm is a sudden, severe headache.Can have no symptoms, but people may experience:Headache: can be severeGastrointestinal: nausea or vomitingAlso common: bleeding, dizziness, light sensitivity, headache, stiff neck, or thunderclap headache