What Are Cluster Headaches?

Severe headaches can ruin your day, no matter what causes them. Painful, frequent headaches can get in the way of living. Cluster headaches are one type of severe, frequent headache that can leave people feeling helpless.

Here’s what you should know about cluster headaches, according to Suhag Patel, PA-C, certified physician assistant, UPMC Neurological Institute.

What Are Cluster Headaches?

Cluster headaches are one of the most severe types of headaches.

Most people never get these kinds of headaches; cluster headaches are rare. According to the National Library of Medicine, only 0.1% of people get cluster headaches.

Cluster headaches are the most common trigeminal autonomic cephalgia headache (TACs) that we know of.

“Cluster headaches are much more painful than regular, tension-type headaches,” Suhag says. “Tension-type headaches cause mild or dull pressure without any other symptoms.”

In cluster headaches, the pain is often unbearable. And they cause other symptoms.

Signs of cluster headaches

When people get cluster headaches, they get severe pain on one side of their head. Each episode is painful but doesn’t last long. Most cluster headache attacks last from 15 minutes to three hours.

Cluster headache attacks can occur:

  • Every other day.
  • Often at the same time every day, most often at night.
  • Repeatedly for weeks to months at a time.
  • Up to eight times in one day. Most people have them twice a day.

People can go months or years without getting cluster headache attacks. The name for this is remission.

For many people, cluster headache attacks come back at some point. The pattern of attacks and remission often lasts up to 15 years.

Symptoms of cluster headaches

Along with extreme pain, a cluster headache will cause at least one of the following symptoms. They will show on the same side as the headache:

  • Bloodshot or watery eyes.
  • Ear fullness (the feeling of clogged ears).
  • Eyelid dropping.
  • Forehead or facial swelling.
  • Nasal congestion or runny nose.
  • Smaller eye pupil.
  • Swollen eyelids.

People with cluster headaches can also have allodynia, nerve pain caused by something that often doesn’t cause pain. For example, a touch of a feather can cause them to feel pain.

“Symptoms of cluster headaches are often confused with other health issues,” Suhag says. “This can lead to a misdiagnosis.”

Nasal congestion is often confused with a sinus headache. For sinus headaches, doctors may recommend taking nasal decongestants. These medications won’t work for cluster headaches.

Cluster headache vs. migraine

Cluster headaches can often get confused with migraine headaches. Migraines cause moderate to severe pulsing or throbbing pain. The pain is often in one part of the head but can shift from one side to another.

Migraine pain can last from four hours to a week. You can get these headaches two to four times a month. Symptoms of migraine headaches include:

  • Dizziness.
  • Fatigue.
  • Loss of appetite.
  • Nausea, vomiting, or abdominal pain.
  • Sensitivity to noise, light, or odors.
  • Visual disturbances called auras. This includes seeing bright flashing dots or lights, blind spots, or wavy or jagged lines.

Each cluster headache attack doesn’t last as long as a migraine attack. The longest an attack will last is three hours.

People with migraines often feel better if they lie still. People with cluster headaches often can’t sit still because of intense pain. They are often restless or anxious.

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Cluster Headache Causes

Since cluster headaches are rare, studying why and how people get them is hard. There’s not enough research on cluster headaches to know what causes them.

Researchers suspect genetics may play a role in who gets cluster headaches.

Who is at risk of getting cluster headaches?

Several things can raise your chance of getting cluster headaches. According to the National Library of Medicine, you are more likely to get cluster headaches if:

  • You are 30 or older — You can get cluster headaches at any age. But they often start around age 30.
  • You are male — Men are three times more likely than women to get cluster headaches.
  • You drink alcohol.
  • You have a family history — You are more likely to get cluster headaches if a biological parent or sibling gets them.
  • You have had brain trauma or brain surgery.
  • You have sleep apnea — Between 30% and 80% of people with cluster headaches also have sleep apnea.
  • You smoke — Up to 88% of people who have cluster headaches smoke cigarettes.

Triggers for cluster headaches may include:

  • Alcohol use.
  • Glare from the sun or light.
  • Higher stress levels.
  • Hot weather.
  • Sexual activity.
  • Using nitroglycerin.
  • Watching television.

Are Cluster Headaches Dangerous?

Cluster headaches cause extreme pain. People with cluster headaches often pace or rock back and forth to deal with the pain. Some people may bang their heads to distract themselves from the pain.

Severe pain can lead to mental health issues. During cluster headache attacks, many people have thoughts of suicide or self-harm. But the risk of suicide is low.

When Should You See Your Doctor About Cluster Headaches?

“You should see your provider if headaches get in the way of life or if you have cluster headache symptoms,” Suhag says. “They can make sure nothing else is going on with your health. They can also suggest treatment that may help.”

Treatment for a cluster headache attack is 100% oxygen therapy. At least 66% of people with cluster headaches can benefit from oxygen therapy, according to the National Library of Medicine. It often works in less than 10 minutes.

Other drug treatments for an attack include:

  • Ergotamine.
  • Intranasal lidocaine.
  • Intranasal triptans.
  • Octreotide.

Cluster headaches are often difficult to treat. According to the National Library of Medicine, up to 20% of people with cluster headaches develop drug resistance. These medications stop working for them.

Treatments to prevent cluster headache attacks include:

  • Glucocorticoids, such as oral prednisone.
  • Intranasal capsaicin.
  • Lithium.
  • Melatonin.
  • Suboccipital blockade.
  • Valproic acid.
  • Verapamil.

When drugs no longer work, deep brain stimulation may help.

Editor's Note: This article was originally published on , and was last reviewed on .

Cluster Headache. StatPearls. National Library of Medicine. Link.

Allodynia. StatPearls. National Library of Medicine. Link.

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