Thunderclap headache

Overview
A thunderclap headache is a sudden and severe headache. Since it is sometimes a sign of a medical emergency, one should "seek immediate medical attention for any headache that comes on suddenly and severely."

The name "thunderclap" signifies the intensity and acuity of such headaches. In 25% of cases, a thunderclap headache is an indication of aneurysmal subarachnoid hemorrhage (SAH), which often leads to death or severe disability. Headaches which accompany SAH are "frequently described as being the worst headache of one's life, although other clinical presentations are possible."

Diagnosis
Diagnosis is made via a process of exclusion with accompanying negative computed tomograph and lumbar puncture results.