Cluster Headache - The Basics - Updated

Patient Expert
Medically Reviewed

Cluster headaches are often said to be the most painful of all headaches. They have been described as "boring," "burning," "like a hot poker in the eye," and as "suicide headaches." The age of onset of cluster headaches is most often between the ages of 20 and 40, and they are more common in men than women at a ratio of 2:1. For many years, that ratio was stated to be 3:1. Researchers theorize that women have long been misdiagnosed because cluster headaches were thought to be so predominantly found in men.

Cluster headache symptoms:

Cluster headaches are attacks of severe pain lasting 15 to 180 minutes and occurring from once every other day up to eight times in one day.

The pain is:

  • severe
  • unilateral
  • orbital (near the orbit, the bone framing the eye), supraorbital (above the orbit), temporal (at the temple), or a combination of those sites.

These attacks also include one or more of these symptoms ipsilaterally (on the same side as the pain):

Most cluster headache patients are restless or agitated during attacks and find it hard to be still. Cluster sufferers characteristically pace the floor during an attack.

Cluster headaches are diagnosed as "episodic" when the attacks occur in periods lasting seven days to one year, separated by pain-free periods lasting one month or longer. In "chronic" cluster headaches, attacks occur for more than one year without remission or with remissions lasting less than less month.

The term cluster headaches comes from the attacks usually occur in series (cluster periods) lasting for weeks or months separated by remission periods usually lasting months or years. However, about 10–15 percent of patients have chronic symptoms without remissions.

There are no diagnostic tests to confirm cluster headaches. Diagnosis is accomplished by reviewing the patient's personal and family medical history, studying their symptoms, and conducting an examination. Cluster headache is then diagnosed by ruling out other causes for the symptoms.

Treatment of cluster headaches:

The most commonly used therapies to shorten or abort a cluster attack are:

  • 100 percent oxygen administered by mask
  • sumatriptan (Imitrex, Imigran) nasal spray or subcutaneous injection
  • DHE-45 subcutaneous injection

The most commonly used preventive medications are:

For consistency in diagnosing and classifying head pain disorders, the International Headache Society’s International Classification of Headache Disorders, 3rd Edition (ICHD-3), is generally accepted as the “gold standard.” This provides standardization of diagnoses, providing guidance and reducing confusion.

Information on cluster headaches from the ICHD-3:

Previously used terms:

Ciliary neuralgia; erythro-melalgia of the head; erythroprosopalgia of Bing; hemicrania angioparalytica; hemicrania neuralgiformis chronica; histaminic cephalalgia; Horton’s headache; Harris-Horton’s disease; migrainous neuralgia (of Harris); petrosal neuralgia (of Gardner); Sluder’s neuralgia; spheno-palatine neuralgia; vidian neuralgia


"Attacks of severe, strictly unilateral pain which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15–180 minutes and occurring from once every other day to eight times a day. The pain is associated with ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis and/or eyelid oedema, and/or with restlessness or agitation."

Diagnostic criteria:

  1. At least five attacks fulfilling criteria B-D
  2. Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15–180 minutes (when untreated)
  3. Either or both of the following:
    1. At least one of the following symptoms or signs, ipsilateralto the headache:
      1. conjunctival injection and/or lacrimation
      2. nasal congestion and/or rhinorrhoea
      3. eyelid oedema
      4. forehead and facial sweating
      5. forehead and facial flushing
      6. sensation of fullness in the ear
      7. miosis and/or ptosis
    2. a sense of restlessness or agitation
  4. Attacks have a frequency between one every other day and eight per day for more than half of the time when the disorder is active
  5. Not better accounted for by another ICHD-3 diagnosis.


During part (but less than half) of the time-course of 3.1 Cluster headache, attacks may be less severe and/or of shorter or longer duration.

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