A severe headache that can be characterized as “thunderclap” or “worst headache of life” is considered an emergency.  This can be a sign of a hemorrhagic (bleeding) stroke called subarachnoid hemorrhage caused by a brain aneurysm that has burst open.   This is a life-threatening emergency.  Click here to read more about subarachnoid hemorrhage from … More When A Headache Is A Life-Threatening Emergency