What Are Cluster Headaches?

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What Are Cluster Headaches?

Cluster headaches, as the name suggests, are a series of headaches that occur in groups, or clusters. They can range in frequency from multiple times a day to every few days.

Cluster headaches are rare; they affect one in 1,000 people. They can cause severe pain on one side of the head, typically around the eye. These headaches can be mistaken for other types of headaches, like sinus headaches, migraine headaches, or tension headaches.

This article explores the symptoms, causes, diagnosis, and treatment of cluster headaches.

Symptoms of Cluster Headaches

These are some of the symptoms of cluster headaches:

  • A sudden burning or piercing pain 
  • Pain around or behind one eye, that may also spread to the forehead, nose, temple, jaw, or neck on that side of the face
  • Redness, watering, or pain in the affected eye
  • Smaller pupil size in the affected eye
  • Swollen or droopy eyelids
  • Stuffy or runny nose, particularly on the side of the head that hurts
  • Flushed face or excessive sweating
  • Agitation or restlessness, that may be characterized by pacing or rocking rather than sitting or lying down while the headache is ongoing

Each headache can last anywhere between 15 minutes and three hours. The pain usually reaches its peak intensity within five or 10 minutes.

Cluster headaches typically develop a pattern and appear at the same time or in the same manner, sometimes for weeks or months at a time. A period of cluster headaches can be followed by a period of remission, without any headaches for months or years.

Some people experience cluster headaches at night, after going to bed—these nighttime headaches can feel even more severe than headaches experienced during the day.

Causes of Cluster Headaches

Cluster headaches are caused by a sudden release of histamine (a chemical the body produces during an allergic reaction) or serotonin (a chemical produced by nerve cells). An area of the brain known as the hypothalamus plays a role in triggering the release of these chemicals, which affect the trigeminal nerve (a cranial nerve) in the face. 

The exact reasons why this happens aren’t fully understood yet; however, these are some factors that may trigger or exacerbate the headaches:

  • Alcohol consumption
  • Cigarette smoking
  • Cocaine use
  • Foods containing nitrates
  • Exercise or physical exertion
  • Certain medications
  • High altitude
  • Bright light
  • Heat

Cluster headaches may run in families. They may first start to appear between the ages of 20 and 40. They are more common in people who have sleep apnea, and those who smoke or drink regularly. According to a 2018 study, men are more likely to experience cluster headaches than women.

Diagnosing Cluster Headaches

If you have been experiencing a pattern of frequently recurring headaches, you should visit a specialist, such as a neurologist or headache specialist, or contact your primary care physician for a referral.

The diagnostic process may involve:

  • A detailed family and personal medical history
  • A physical examination, which can reveal indicators like a small pupil or drooping eyelid if the headache is ongoing
  • An account of your symptoms
  • Imaging tests such as an MRI, which can help rule out other medical conditions

Treating Cluster Headaches

Over-the-counter pain medication or narcotic painkillers may not help with cluster headaches as they can take time to provide relief. Therefore, it’s important to see a specialist for treatment options. 

Treatment generally focuses on providing relief for cluster headaches once they start, and preventing future headaches.

These are some of the treatments that can help with cluster headaches:

  • Injections or nasal sprays: Your healthcare provider may give you an injection or a nasal spray of medicines such as sumatriptan, zolmitriptan, or dihydroergotamine, for rapid relief from an ongoing headache.
  • Oxygen therapy: Breathing in pure oxygen through a face mask can also help relieve an ongoing headache.
  • Other medication: Other types of medicines, such as allergy medication, blood pressure medication, antidepressants, anti-inflammatory medication and seizure medication may help prevent and treat cluster headaches.
  • Physical therapies: Physiotherapy, acupuncture, and chiropractic adjustment are physical therapy options that may help with the headaches.
  • Surgery: If other treatments are not helping, your healthcare provider may suggest surgically implanting a neurostimulator into your body. A neurostimulator is a device that delivers tiny electrical signals to your nerves.

You may need more than one type of treatment to treat your headaches. You may have to try different types of medications before your healthcare provider is able to determine which one works best for you.

Preventing Cluster Headaches

These are some steps you can take to prevent cluster headaches.

Avoid Triggers

If you’re prone to cluster headaches, it may be helpful to avoid smoking and drinking alcohol. Additionally, if you’ve identified any foods or other factors that trigger your headaches, it’s best to avoid those as much as possible.

Maintain a Headache Diary

Maintain a journal where you note down the details of your headaches, to help you and your healthcare provider identify patterns and triggers.

For each instance, include information about: 

  • Which parts of your head hurt 
  • How intense the pain is
  • What time the headache started
  • How long the headache lasted
  • How long it’s been since your last headache
  • What you ate and drank that day
  • How much sleep you got the night before
  • Where you were and what you were doing when the pain started
  • What made the headache stop

A Word From Verywell

While everyone gets headaches from time to time, cluster headaches are a rare type of recurring headache that causes intense pain. These headaches do not cause permanent damage to the brain and are not life-threatening. However, they can be debilitating and make it hard for you to function. If you think you might be experiencing cluster headaches, it's important to reach out to your doctor so you can be treated and get relief as soon as possible.

2 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. May A, Schwedt TJ, Magis D, Pozo-Rosich P, Evers S, Wang SJ. Cluster headache. Nat Rev Dis Primers. 2018;4:18006. doi:10.1038/nrdp.2018.6

  2. Wei DYT, Yuan Ong JJ, Goadsby PJ. Cluster headache: epidemiology, pathophysiology, clinical features, and diagnosis. Ann Indian Acad Neurol. 2018;21(Suppl 1):S3-S8. doi:10.4103/aian.AIAN_349_17

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By Sanjana Gupta
Sanjana is a health writer and editor. Her work spans various health-related topics, including mental health, fitness, nutrition, and wellness.