A thunderclap headache is a severe headache that starts suddenly. This type of headache pain doesn’t gradually build in intensity. Instead, it’s an intense and very painful headache as soon as it starts. In fact, it’s frequently described as the worse headache of one’s life.

A thunderclap headache may be a sign of a condition that can be life-threatening. It may be connected to some sort of bleeding in your brain. It’s important that you seek medical attention if you think you may be experiencing one. It may also have a benign cause that’s not life-threatening but should still be checked immediately to find out what’s causing it.

The symptoms of a thunderclap headache are similar no matter what the cause is. These symptoms can include:

  • severe headache pain that starts out of nowhere
  • vomiting and nausea
  • fainting
  • feeling as if it’s the worst possible headache you’ve ever had
  • pain felt anywhere in your head
  • headache pain including your neck or lower back

It may be triggered by certain activities or have no trigger at all.

A thunderclap headache will normally reach its worst point after just 60 seconds. Many times, it’ll start to go away about an hour from the point of the worst pain, but sometimes it may last for a week or more.

Most thunderclap headaches aren’t the same as a migraine. However, it’s common for those that experience thunderclap headaches to have had frequent migraines in the past.

The biggest difference between a severe migraine and a thunderclap headache is the severity of the pain. The pain of a thunderclap headache will be the worst headache pain you’ve ever felt. This is true even for those who have migraines. A thunderclap headache can also feel similar to a “crash” migraine. Only tests performed by a medical professional can determine which type of headache you’re having.

If tests reveal that your thunderclap headache doesn’t have a life-threatening cause, then it may be a disorder that’s considered a type of migraine headache.

A thunderclap headache is most commonly a symptom of a subarachnoid hemorrhage or bleeding in the brain, which can be life-threatening if not treated quickly. The most common cause of this type of bleeding is a ruptured aneurysm in the brain. Other serious and possibly life-threatening causes may include:

In some cases, a physical cause for your thunderclap headache may not be found. These types of thunderclap headaches are considered to be due to an idiopathic benign recurrent headache disorder. This disorder is a type of migraine headache and is usually not life-threatening. This disorder can only be diagnosed after testing for all other causes.

While there may not be a cause for this type, there are some things that are common triggers. These triggers include:

  • sexual activity
  • physical activity
  • a bowel movement that causes you to strain
  • injury

The first step in treating thunderclap headaches is to determine the cause. After a physical evaluation and gathering information about your symptoms, your doctor will usually start with a CT scan. CT scans will often be enough for your doctor to determine the cause. However, if it doesn’t give them a clear cause, you’ll have additional tests done. Some of these tests include:

  • Magnetic resonance imaging (MRI). An MRI can help your doctor to see the structures of your brain.
  • Magnetic resonance angiography (MRA). An MRA maps the blood flow in your brain using an MRI machine.
  • Lumbar puncture. A lumbar puncture, commonly referred to as a spinal tap, removes a sample of blood or fluid from your spinal cord which will then be tested. This fluid is the same as what’s surrounding your brain.

There are multiple treatment possibilities based on what’s causing your thunderclap headaches. The treatments focus on treating the cause of your headache. Treatments may include:

  • surgery to repair a tear or blockage
  • medications to control blood pressure
  • pain medications to control recurrent thunderclap headaches, especially those that have a specific trigger

This isn’t a complete list of treatment options for a thunderclap headache. Your doctor will advise you of treatment options based on the specific cause of your headaches.

Many causes of thunderclap headaches are life-threatening if not diagnosed and treated promptly. Conditions that may be associated with thunderclap headaches include:

  • strokes
  • migraines
  • head injury
  • high blood pressure

You should seek medical help immediately when you first experience a severe and sudden headache of any kind. This type of headache can be a sign or symptom of a life-threatening condition.

Some causes of a thunderclap headache may not be life-threatening. However, only a medical professional can determine what’s causing your headache.

If you seek medical help immediately when you experience a thunderclap headache, the cause can usually be effectively treated or managed. However, delaying medical treatment could be fatal.

If you experience regular migraines, you should still seek medical attention as soon as possible if you have a sudden and severe headache that’s worse than any other migraine in your past.