Thunderclap headache: Causes, symptoms, diagnosis, and treatment

thunderclap headacheWhen someone has a severe headache that hits out of nowhere, with sudden pain, it is likely a thunderclap headache. But just what is a thunderclap headache?

Well, as the name suggests, it is a headache that does not include any warning signs and catches the sufferer unaware. The pain is sudden, reaching its peak intensity within 60 seconds.


A thunderclap headache can be a sign of a life-threatening illness or a headache disorder. No matter what the cause, it is important to get to a doctor if you ever experience such a headache.

A thunderclap headache is rare, but those who have suffered from this type of headache have reported that the pain generally lasts about one hour. There are cases where thunderclap headaches have lasted over a week.

The thunderclap headache got its name from two neurologists at the University of California, San Francisco. They came up with the name after taking care of a patient in 1986 who reported sudden, severe head pain due to an aneurysm that had not yet ruptured. A brain aneurysm or cerebral aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain.

Thunderclap headache prevalence

About 90 percent of the population experiences some kind of headache from time to time. Tension headaches and migraines are the most common type of headaches. Thunderclap headaches are less common. In fact, they occur in about 43 out of 100,000 adults in the developed world.

Any thunderclap headache, even in those who regularly suffer from headaches, needs to be assessed to determine the cause. One of the biggest concerns with thunderclap headache is that it can be a sign of subarachnoid hemorrhage (SAH), which is essentially due to a blood clot in the brain.

Although headaches are a common complaint among people who are seen in emergency departments, most are benign headaches. In fact, studies show that only about 10 percent are due to an underlying condition.

What are thunderclap headaches?

Doctors are often asked, “What is a thunderclap headache?” It is difficult for them to give a full description, because each individual’s headache is different. The reason is that thunderclap headaches can either have no detectable cause or there can be a specific cause. To fully understand this type of headache, we have to look at potential thunderclap headache causes, including some that are life-threatening.

Thunderclap headache causes:

  • Internal bleeding in the brain or within the membranes covering the brain
  • A ruptured blood vessel in the brain
  • A brain aneurysm that has not ruptured yet
  • A tear in the lining of any artery supplying blood to the brain
  • A tear in the covering of a spinal root
  • A tumor in the third ventricle of the brain
  • Internal bleeding in the pituitary gland
  • A blood clot in the brain
  • Extremely high blood pressure
  • Infections, such as encephalitis and meningitis
  • Stroke

Related: Hypertension headache: How to identify if high blood pressure is the cause

Overexertion and sexual activity are also known to cause thunderclap headache. Many people who have no other underlying reason for a headache recall experiencing a trigger event, like exertion, sexual activity, or emotional upset.

Symptoms of thunderclap headaches

We have already established that this type of headache comes on suddenly like a lightning strike, but let’s look at some of the specific thunderclap headache symptoms:

  • Intense headache pain
  • Peak pain within 60 seconds
  • Headache pain for an hour or up to 10 days
  • Pain in the neck area
  • Nausea and vomiting
  • Weakness
  • Visual impairment
  • Loss of consciousness, if related to SAH

Thunderclap headache test and investigation

When a sudden, severe headache strikes, it is important to begin investigation right away to rule out any life-threatening causes. There are a number of different methods doctors can use to help determine why you might be suffering from a thunderclap headache. The list below explains tests in brief.

  • CT Scan: Computerized tomography (CT) can scan the head to help identify headache causes. Sometimes an iodine-based dye is used to enhance the image.
  • MRI: Magnetic resonance imaging (MRI) provides a detailed view of the structures inside the brain.
  • MRI Angiography: This type of MRI helps map blood flow inside the brain.
  • Spinal Tap: This is also referred to as a lumbar puncture. It allows for the removal of a small amount of fluid surrounding the brain and spinal cord so it can be tested for infection or bleeding.
  • Catheter Angiography: During this procedure, a thin tube (catheter) is inserted into an artery through a tiny incision in the skin. The catheter is guided to a specific area in the body to be examined. A contrast material, which is injected into the patient, helps with the capturing of images using a small dose of ionizing radiation (x-rays).
  • CSF Spectrophotometry: Cerebrospinal fluid testing or CSF spectrophotometry is a method that is used to detect suspected intracranial bleeding, such as SAH. This spectrophotometry procedure is said to be the most sensitive procedure for patients who experience symptoms late. For example, one to two weeks after the bleed. CSF is done using a double beam spectrophotometer.

According to the journal Stroke, all patients who experience acute severe head pain should be examined for the possibility of SAH. For many, this can mean getting a CT scan, while others may have to go a step further with spectrophotometry.

Thunderclap headache treatment options

Thunderclap headache treatment will depend on the underlying cause. Getting a quick and proper diagnosis of your headaches is key to proper treatment.

Some serious cases of thunderclap headache require surgery. For instance, if a blood clot is the cause of the headache, surgery is most likely necessary.

On the other hand, if the headache is due to meningitis, treatment could include medications such as antibiotics. Those who suffer from high blood pressure may be prescribed calcium-channel blockers. Some patients, regardless of the cause, are given analgesic drugs, which may help relieve the pain associated with thunderclap headaches. There are also times when a therapeutic lumbar puncture (spinal tap) is used to treat thunderclap headaches.

Taking note of when a thunderclap headache occurs and what you were doing at the time the pain struck can be helpful in both the diagnosis and treatment.

Related: Essential oils for migraines and headaches

Diagnosing thunderclap headaches

Anyone who has experienced a thunderclap headache will probably tell you that the last thing they want to do at the time is think. Yes, thinking when you have severe head pain seems…well, unthinkable. Yet, it is important to do as much thinking about what might have happened as you possibly can on the way to the doctors or while waiting in an emergency room to see a specialist. It is helpful if you can take notes or have someone with you to take notes about the following:

  • Symptoms
  • Recent changes in life
  • Any stress in your life
  • Medications and supplements you are taking
  • What you were doing when the headache suddenly struck
  • Information about your diet and sleep patterns
  • Information about any health conditions you might have
  • Questions you have for the doctor

While you won’t think of everything, consider what the doctor might ask in terms of the headache itself. For example, he or she will likely ask what, if anything, improves the headache pain and what, if anything, makes the headaches worse? Chances are you will be asked to rate the head pain on a scale of one to 10 as well.

Being prepared when the doctor is ready to examine you can be extremely helpful. It can move the examination along and get you closer to a proper diagnosis and pain relief.

While thunderclap headache should not be taken lightly, a large number of people who experience such a sudden and severe onset of headache discover that there is no underlying cause. In other words, it is a mystery headache. The most important point is that if you or anyone you know experiences a headache that sounds like a thunderclap headache, the smart course of action is to get it checked out immediately to determine if you are in the clear or are facing a serious life-threatening situation.



Headache on top of head: Causes and treatment

Headache while sleeping: How to get rid of nighttime headaches


Related Reading:

Hemicrania continua: How to prevent and treat persistent unilateral headaches naturally

Headache behind ears: Causes, symptoms, diagnosis, treatment, and prevention

Popular Stories