What is a thunderclap headache?

A thunderclap headache is an extremely painful headache that comes on suddenly, like a clap of thunder. This type of headache reaches its most intense pain within 1 minute and lasts at least 5 minutes.

Thunderclap headaches strike without any warning. Some of these headaches are benign (not dangerous). But they can also be a sign of very serious underlying conditions that involve bleeding in and around the brain.

It is important to seek medical attention immediately to rule out life-threatening causes of a thunderclap headache.

How common is a thunderclap headache?

Thunderclap headaches are rare. They occur in less than 50 out of 100,000 adults each year.

What causes a thunderclap headache?

Some thunderclap headaches have no known cause and are not dangerous. Others occur because of a problem with the blood vessels in the brain or due to injury or heavy exertion. Causes of thunderclap headaches include:

  • Torn or ruptured blood vessels in the brain
  • Stroke (blocked or bleeding blood vessel)
  • Brain aneurysm (bulging or bleeding blood vessel)
  • Head injury that causes a brain bleed
  • Vasculitis (swollen blood vessel)
  • Infection in the brain such as encephalitis or meningitis
  • Sudden severe rise in blood pressure
  • Late-term pregnancy complications including rise in blood pressure and bleeding in the brain’s pituitary gland during pregnancy or soon after delivery
  • Spasms in the blood vessels around the brain (vasoconstriction syndrome)

What are the symptoms of a thunderclap headache?

The main symptom of a thunderclap headache is sudden and severe pain in the head. This pain reaches its most intense point within 60 seconds and lasts at least 5 minutes. Other symptoms may include:

  • Numbness
  • Weakness
  • Speech problems
  • Nausea and/or vomiting
  • Seizures
  • Change in vision
  • Confusion
  • Change in sensation

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