Cluster Headache FAQs

  • Medical Author: Edward Lubin, MD, PhD
  • Medical Editor: Joseph Carcione Jr, DO, MBA
  • Medical Editor: Francisco Talavera, PharmD, PhD
  • Medical Editor: James H Halsey, MD
Reviewed on 11/4/2021

What Facts Should I Know about Cluster Headaches?

A person may have several headaches a day for weeks or months, usually separated by headache-free periods of varying duration. Many more people have migraine or tension headaches than cluster headaches.
  • Cluster headache is an uncommon condition characterized by short-lived attacks of sudden, severe pain around one of the eyes. The word cluster is used because these headaches typically come in groups or bunches. A person may have several headaches a day for weeks or months, usually separated by headache-free periods of varying duration. Many more people have migraine or tension headaches than cluster headaches.
  • The International Headache Society (IHS) classifies cluster headaches as episodic (occurring in cycles) or chronic (long-term without significant breaks).
  • Episodic cluster headaches are defined as those that occur in periods (clusters) lasting from 7 days to 1 year. Clusters are separated by headache-free intervals lasting at least 2 weeks. Clusters usually last 2 weeks to 3 months.
  • Chronic cluster headaches are defined as those that occur for more than 1 year without remission (intervals in which headaches do not occur) or with remissions lasting less than 2 weeks. Chronic headaches are classified as those that are chronic from the start and those that develop from episodic headaches. Chronic cluster headaches are very hard to treat, and standard preventive drugs often do not help people with this type of cluster headache.
  • If a person has the following signs and symptoms, he or she might have what is called symptomatic cluster-like headaches.
    • Lack of a periodic pattern (a pattern that runs in cycles)
    • Continuing low-intensity headaches between high-intensity headaches
    • Partial or little response to standard treatments
    • Weakness or other signs on one side

How Dangerous Are Cluster Headaches?

Despite the intense pain of cluster headaches, they are not life-threatening. They are harmful to a person’s quality of life, however, and sometimes induce depression and/or anxiety disorders, especially if the headaches are uncontrolled by medication or other therapies. Doctors conduct thorough examinations of persons with cluster headaches in order to rule out truly life-threatening causes of headaches like tumors or subarachnoid hemorrhages (bleeding in the membranes of the brain).


A migraine is a result of neurological (nerve) dysfunction. See Answer

What Causes Cluster Headaches?

No one knows exactly what causes cluster headaches, although many theories have been put forth. They are probably caused by complex, interacting abnormalities in the blood vessels, nerves, and chemicals in the head, brain, and face.

Many experts believe that cluster headache and migraine headache share a common cause that begins in the trigeminal nerve, which is the nerve that carries sensation about the head, brain, and face, and ends with the blood vessels surrounding the brain. Other authorities believe that cluster headache pain comes from within the deep vascular channels in the head (for example, the cavernous sinus) and does not involve the trigeminal system.

Cluster headaches have been reported to affect many members of the same family. This suggests that some people might have an inborn tendency to get this type of headache.

Cluster headaches may be triggered by

  • stress, relaxation,
  • extreme temperatures,
  • glare,
  • allergic rhinitis (hay fever), and
  • sexual activity.
  • Eating certain foods may sometimes cause them.
  • Using alcohol- or tobacco-containing products worsens cluster headaches.

What Are the Symptoms of Cluster Headaches?

A cluster headache attack is a dramatic event. The pain usually peaks in a few minutes, but attacks can last from 5 minutes to 3 hours and can occur from once every other day to 8 times a day. Unlike migraine headaches, cluster headaches are not preceded by auras (visual or other types of sensory disturbance), so people usually have little or no warning that one is about to happen. A unique feature of cluster headaches is that they often begin while a person is sleeping.

The pain and location of cluster headaches are its most important defining features. The pain is generally described as excruciating, explosive, deep, and/or piercing (but usually not throbbing). Some people say that it feels as if an ice pick were being driven into their eye. This stabbing eye pain may feel like an electric shock, which may last for a few seconds, followed by a deeper element that continues for a half hour or longer. The pain almost always begins in or around an eye and always on one side of the face. For most people, the pain stays on the same side of the face from one cluster headache to another, while in a small minority, the pain switches from side to side from one headache to the next.

The pain may spread to other parts of the face and neck but usually remains centered around one of the eyes. A person experiencing a cluster headache may be very restless. Some people bang their heads against a hard surface or sit, rock, or pace.

Cluster headaches are often associated with the following physical signs and symptoms:

  • Ipsilateral nasal congestion and rhinorrhea (stuffy and runny nose on the same side as the pain around the eye)
  • Lacrimation (watery, tearing eyes)
  • Conjunctival hyperemia (increased blood flow to the membranes lining the eyeball and the inside of the lids)
  • Facial diaphoresis (sweaty face)
  • Palpebral edema (swollen eyelids)
  • Complete or partial Horner syndrome (a condition causing ptosis [eyelid closure], change in pupil size on one side of the face, and lack of sweating) that may persist between attacks
  • Tachycardia (fast heartbeat)

Between attacks, people with cluster headaches usually have normal physical examination findings.

Who Gets Cluster Headaches?

Cluster headaches affect less than 1% of the population. Many more men than women suffer from them. (The male-to-female ratio may be as much as 5-8:1.) Most people have their first cluster headache during their mid-twenties, although some have the first attacks in their teens or early fifties. Most people seem to have their most frequent attacks during middle age.

People who get cluster headaches often have a distinctive face. Typically, they are tall and rugged looking and have the following features:

  • Leonine (lionlike) facial appearance
  • Thickened skin with lots of very noticeable wrinkles
  • Broad chin
  • Vertical forehead creases
  • Nasal telangiectases (lesions formed by widened capillaries or small arteries)
    • These are largely the result of long-term heavy smoking.
    • Smoking worsens cluster headache symptoms.

Should a Person with Cluster Headaches See a Doctor?

Yes. Because of the severity of cluster headaches, the vast majority of people who have them seek medical care very soon. Those who do not must understand that a full evaluation by a doctor is needed to rule out the rare cases of cluster headache-like symptoms that might indicate meningitis (inflammation of the membranes of the brain or spinal cord), subarachnoid hemorrhage (bleeding in the brain), or brain tumor.

A doctor should be called if a person has any of the following problems:

  • A change in frequency, severity or features of the headaches typically experienced
  • A progressively worsening headache that lasts for days
  • A headache brought on by what doctors call Valsalva maneuvers (coughing, sneezing, bearing down, straining while on the toilet)
  • Unintentional great weight loss
  • Weakness or paralysis that lasts after a headache stops

Persons with any of the following problems should go or be taken to a hospital emergency department:

  • The worst headache of a person’s life, especially if the headache comes on suddenly
  • Headache associated with trauma to the head
  • Trauma to the head with loss of consciousness
  • Fever or stiff neck associated with a headache
  • Decreased level of consciousness or confusion
  • Paralysis on one side of the body
  • Seizures


16 Surprising Headache Triggers and Tips for Pain Relief See Slideshow

What Tests Are Done for People with Cluster Headaches?

Doctors reach a diagnosis of cluster headache entirely on the basis of the signs (what doctors find on examination) and symptoms (what patients report) of the condition. Rarely, the signs and symptoms caused by tumors or other masses mimic those of cluster headaches. In these uncertain cases, doctors will order a CT scan or MRI (which shows images of the inside of the body).

Sometimes, a lumbar puncture (spinal tap) is needed. This procedure may help confirm if an individual's cluster headaches are caused by an infection or by bleeding in or around the brain.

These tests are necessary because people with the following medical problems can have signs and symptoms that may be mistaken for those of cluster headaches:

  • Meningiomas of the cavernous sinus (a benign [relatively harmless] tumor in a certain part of the brain)
  • Arteriovenous malformations (blood vessel defects)
  • Pituitary adenomas (benign tumors of the pituitary gland)
  • Nasopharyngeal carcinoma (cancer in certain parts of the nasal passages and neck)
  • Vertebral artery aneurysms (bulging in certain arteries of the head and neck)
  • Metastatic carcinoma of the lung (spreading lung cancer)
  • Subarachnoid hemorrhage (bleeding in the membranes of the brain

How Are Cluster Headaches Treated?

People with cluster headaches usually receive drug therapies, although surgery and alternative treatments have helped some people. Drug treatments of cluster headaches may be classified as symptomatic (abortive) or preventive. Abortive treatment is directed at stopping or reducing the severity of an attack, while preventive treatment is used to reduce the frequency and intensity of individual headache bouts.

Because of the short-lived nature of cluster headaches, effective preventive therapy is the cornerstone of treatment for persons who have frequent attacks that affect their quality of life. Preventive therapy should begin at the start of a cluster headache cycle and continue until the person is free of headaches for at least 2 weeks. The dosage of the preventive drug may then be slowly tapered. This helps prevent a return of headaches.

Some drugs might work well for one person but not for another. Several may have to be tried before a person finds the right one.

The short-lived and unpredictable nature of cluster headaches makes oral narcotic (opioid) analgesics far less useful for treatment than other agents. Despite this, some desperate individuals with cluster headaches take (and sometimes abuse) these substances.

Abortive treatments

Inhalation of high-flow, the concentrated oxygen is extremely effective in stopping a cluster headache attack and is the treatment of choice. Although oxygen is readily available in emergency departments, its widespread use in the home setting is limited by safety concerns and other reasons.

An occipital nerve steroid injection of methylprednisolone acetate (Depo-Medrol) may stop a cluster headache attack.

The following are abortive drugs in the triptan class. They are used to stop cluster headache attacks in progress, but they have little preventive value.

The following nontriptans are also used to stop attacks. They are sometimes effective when triptans fail.

Preventive treatments

People who have frequent cluster headache attacks and report that the attacks affect the quality of life should use preventive therapy as the main element of their treatment plan. Specific headache-stopping drugs (abortive treatments) may also be taken as necessary.

The goals of preventive therapy include decreasing the frequency and severity of acute attacks and improving quality of life.

The choice of preventive medication should be tailored to the individual's profile, taking into account comorbidities (concurrent medical conditions) such as depression, weight gain issues, exercise tolerance, asthma, and pregnancy plans. All medications have side effects; therefore, selection must be individualized. Preventive drugs include beta-blockers, tricyclic antidepressants, some anticonvulsants, calcium channel blockers, cyproheptadine (Periactin), and nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Naprosyn). Unlike the specific headache-stopping drugs (abortive drugs), most of these were developed for other conditions and have been coincidentally found to have headache preventive effects. The following drugs also have preventive effects; unfortunately, they also have more side effects:


Some surgical operations have been successful in treating people whose cluster headaches do not respond to standard drug treatments. These procedures include nerve blocks and ablative neurosurgical procedures (operations that involve the removal or destruction of a part of the brain, the spinal cord, or a nerve). Radiosurgery (a type of surgery that uses radiant energy and does not involve cutting) has recently been used to provide a less invasive alternative for people who have persistent cluster headaches.

Alternative treatments

Some people with cluster headaches have been helped by alternative or complementary therapies such as chiropractic, acupuncture, osteopathic manipulation, and herbal remedies, though none of these treatments is supported by reliable scientific evidence.

What Can Be Done to Prevent Cluster Headaches?

People with cluster headaches should remember to take prescribed medications at the doses and times the doctor specifies.

As previously noted, cluster headaches may be triggered by stress, relaxation, extreme temperatures, glare, allergic rhinitis (hay fever), and sexual activity. Eating certain foods sometimes brings on an attack, as does the use of alcohol- or tobacco-containing products. Although avoiding all these triggers all the time is not practical or even possible, people with cluster headaches should try to identify and avoid triggers sure to bring on a headache. Prevention is the best treatment available.

Smoking and high blood pressure can worsen cluster headaches, so it is very important to quit smoking and to lower and control high blood pressure.

Will Cluster Headaches Eventually Go Away on Their Own?

Cluster headaches sometimes resolve on their own, but they are usually lifelong problems. Drug treatment plays a part in changing chronic headaches into episodic ones; otherwise, the drugs available today provide incomplete long-term relief.

Most people with episodic cluster headaches tend to keep that variety, eventually changing to the chronic form in only some cases. Mixed forms sometimes occur. Prolonged, spontaneous remissions (long headache-free periods that occur for unknown reasons) have occurred in up to 12% of subjects in some studies, particularly in those with episodic cluster headaches. Chronic cluster headaches are more stubborn and may persist in this form in about half of those who have them. Much less frequently, the chronic form changes to the episodic form.

People whose chronic headaches start later in life tend to have less favorable outcomes. Males and those with a history of episodic cluster headaches preceding the chronic type also have less favorable outcomes.

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Cluster Headache Symptoms

The pain of cluster headache is its defining and most dramatic feature. This pain comes on without warning (no forewarning symptoms such as the aura in classic migraine) and may begin as a burning sensation on the side of your nose or deep in your eye.

In addition to its one-sidedness, other characteristics separate cluster headaches from other headaches.

  • The headaches commonly come on just after you go to sleep.
  • Often the eye on your affected side will tear.
  • Your eyelid on the affected side will droop.
  • You will experience one-sided nasal stuffiness and runny nose.
  • Cluster headaches have seasonal variations. Most attacks occur in January and July, where the days are in turn the shortest and longest.
Reviewed on 11/4/2021
Medically reviewed by Jon Glass, MD; Board Certification: Neurology


1. Lubin E. Cluster Headache. eMedicine Journal [serial online]. 2003.
2. Mendizabal J. Cluster Headache. eMedicine Journal [serial online]. 2003.
3. No author(s) listed. What Is a Cluster Headache?. UC Davis Health System Medical Conditions A-Z List [serial online]. 2003.