Thunderclap headaches live up to their name, striking suddenly like a clap of thunder. The pain of these severe headaches peaks within 60 seconds.

Thunderclap headaches are uncommon, but they can warn of potentially life-threatening conditions — usually having to do with bleeding in and around the brain. Seek emergency medical attention for a thunderclap headache.


Thunderclap headaches are dramatic. Symptoms include pain that:

  • Strikes suddenly and severely
  • Peaks within 60 seconds
  • Can be accompanied by nausea or vomiting

Thunderclap headaches might be accompanied by other signs and symptoms, such as:

  • Altered mental state
  • Fever
  • Seizures

These signs and symptoms might reflect the underlying cause.

When to see a doctor

Seek immediate medical attention for any headache that comes on suddenly and severely.


There's no obvious cause for some thunderclap headaches. In other cases, a variety of potentially life-threatening conditions might be responsible, including:

  • Bleeding between the brain and membranes covering the brain (subarachnoid hemorrhage)
  • A rupture of a blood vessel in the brain
  • A tear in the lining of an artery that supplies blood to the brain
  • Leaking of cerebrospinal fluid — usually due to a tear of the covering around a nerve root in the spine
  • Death of tissue or bleeding in the pituitary gland
  • A blood clot in the brain
  • Severe elevation in blood pressure (hypertensive crisis)
  • Infection such as meningitis or encephalitis
  • Ischemic stroke