What is a cluster headache

Cluster headaches are rare headaches that occur in cyclical patterns or clusters. Cluster headaches are excruciating attacks of pain in one side of the head, often felt around the eye. The pain usually peaks 5 to 10 minutes after onset, lasts 15 minutes and can continue at that intensity for up to 3 hours ¹. A cluster headache commonly can awaken you in the middle of the night with intense pain in or around one eye on one side of your head.

Cluster headache affects about 1 per 1000 Americans. Cluster headaches generally begin between the ages of 20 and 50 but may start at any age, occur more often in men than in women, and are more common in smokers than in nonsmokers.

Cluster headaches occur on one side of the face, often around or behind the eye. They can last anywhere between 15 minutes and three hours. They can happen as often as 8 times in one day, or once every couple of days. Many people also have, on the same side of the face:

• a red and weepy eye
• a drooping or swollen eyelid
• a runny or blocked nose
• sweaty skin.

People often feel restless and agitated during an attack because the pain is so intense, and they may react by rocking, pacing, or banging their head against the wall.

People who get them find they have frequent headaches for weeks or months, then none for a long time – a remission period when the headaches stop. During remission, no headaches occur for months and sometimes even years. In a few people, the cluster headaches come on continuously. They happen more in the night than during the day, and often at the same time each night. They are very painful.

Fortunately, cluster headache is rare and not life-threatening. Treatments can make cluster headache attacks shorter and less severe. In addition, medications can reduce the number of cluster headaches.

Other names for cluster headache are ²:

• erythroprosopalgia of Bing,
• ciliary or migrainous neuralgia,
• erythromelalgia of the head,
• Horton’s headache,
• histaminic cephalalgia,
• petrosal neuralgia of Gardner,
• sphenopalatine,
• Vidian and Sluder’s neuralgia, and
• hemicrania periodica neuralgiformis.

What causes cluster headaches

Nobody knows what causes cluster headaches, but cluster headache patterns suggest that abnormalities in the body’s biological clock (hypothalamus) play a role.

Cluster headaches sometimes run in families. People who get them are more likely to smoke heavily, drink heavily, drink a lot of caffeine and feel a lot of stress, but they can happen to anybody. Further research on risk factors is needed. Studies have shown family history to be a factor and a genetic cause is strongly suggested.

Risk factors for cluster headache

Risk factors for cluster headaches include:

• Sex. Men are more likely to have cluster headaches.
• Age. Most people who develop cluster headaches are between ages 20 and 50, although the condition can develop at any age.
• Smoking. Many people who get cluster headache attacks are smokers. However, quitting smoking usually has no effect on the headaches.
• Alcohol use. Alcohol can trigger an attack if you’re at risk of cluster headache.
• A family history. Having a parent or sibling who has had cluster headache might increase your risk.

Cluster headache triggers

Unlike migraine and tension headache, cluster headache generally isn’t associated with triggers, such as foods, hormonal changes or stress.

During cluster headache periods any substance that dilates blood vessels (such as alcohol, glyceryl trinitrate and histamine) will trigger an attack. That is drinking alcohol may quickly trigger a splitting headache. For this reason, many people with cluster headache avoid alcohol during a cluster period.

Other possible triggers include the use of medications such as nitroglycerin, a drug used to treat heart disease.

Cluster headache symptoms

Common signs and symptoms

Cluster headaches begin quickly and usually without warning. The pain is very severe and is often described as a sharp, burning or piercing sensation on one side of the head. It’s often felt around the eye, temple and sometimes face. It tends to occur on the same side for each attack. Although you might first have migraine-like nausea and aura.

Common signs and symptoms during a cluster headache include:

• Excruciating pain, generally situated in or around one eye, but may radiate to other areas of your face, forehead, temple, neck, shoulders, cheek and upper gum on same side of face
• Steady rather than throbbing pain
• One-sided pain
• Restlessness
• Excessive tearing
• Redness in your eye on the affected side
• Stuffy or runny nose on the affected side
• Forehead or facial sweating
• Pale skin (pallor) or flushing on your face
• Swelling around your eye on the affected side
• Drooping eyelid
• Attacks of 15 – 180 minutes
• 1-3 attacks per day
• Attacks can occur on consecutive days for 6-8 weeks
• Remission periods of months to years
• Onset of pain about an hour after going to bed.

People with cluster headache, unlike those with migraine, are likely to pace or sit and rock back and forth. Some migraine-like symptoms — including sensitivity to light and sound — can occur with a cluster headache, though usually on one side.

Cluster period characteristics

A cluster period generally lasts from six to 12 weeks. The starting date and the duration of each cluster period might be consistent from period to period. For example, cluster periods can occur seasonally, such as every spring or every fall.

Most people have episodic cluster headaches. In episodic cluster headaches, the headaches occur for one week to a year, followed by a pain-free remission period that can last as long as 12 months before another cluster headache develops.

Chronic cluster periods might continue for more than a year, or pain-free periods might last less than one month.

During a cluster period:

• Headaches usually occur every day, sometimes several times a day.
• A single attack can last from 15 minutes to three hours.
• The attacks often occur at the same time each day.
• Most attacks occur at night, usually one to two hours after you go to bed.

The pain usually ends as suddenly as it began, with rapidly decreasing intensity. After attacks, most people are pain-free, but exhausted.

Cluster headache diagnosis

Cluster headache has a characteristic type of pain and pattern of attacks. Your doctor will talk to you and examine you. A diagnosis depends on your description of the attacks, including your pain, the location and severity of your headaches, and associated symptoms.

How often your headaches occur and how long they last also are important factors.

There is no specific test for cluster headache, but your doctor may do tests to rule out other conditions. Your doctor will likely try to pinpoint the type and cause of your headache using certain approaches.

Neurological examination

A neurological examination may help your doctor detect physical signs of a cluster headache. Your doctor will use a series of procedures to assess your brain function, including testing your senses, reflexes and nerves.

Imaging tests

If you have unusual or complicated headaches or an abnormal neurological examination, your doctor might recommend other tests to rule out other serious causes of head pain, such as a tumor or aneurysm. Common brain imaging tests include:

• CT scan. This uses a series of X-rays to create detailed cross-sectional images of your brain.
• Magnetic resonance imaging (MRI). This uses a powerful magnetic field and radio waves to produce detailed images of your brain and blood vessels.

How to get rid of cluster headaches

There’s no cure for cluster headaches and treatment and prevention of cluster headaches can be difficult. The usual painkillers often don’t work.

The goal of treatment is to decrease the severity of pain, shorten the headache period and prevent the attacks.

There are a range of medicines that can help prevent a cluster starting. Talk to your doctor about these.

Because the pain of a cluster headache comes on suddenly and might subside within a short time, cluster headache can be difficult to evaluate and treat, as it requires fast-acting medications.

If you are in the middle of a cluster, you can reduce your chances of having a headache by getting plenty of sleep, and sleeping at the same time each night, and also by avoiding alcohol completely. You should also try to get regular sleep, avoid stress or strenuous physical activity, and avoid a high altitude.

If you get a cluster headache, then you can try:

• medicines – talk to your doctor
• oxygen through a mask
• a nasal spray of local anesthetic.

Talk to your doctor about these.

Some types of acute medication can provide some pain relief quickly. The therapies listed below have proved to be most effective for acute and preventive treatment of cluster headache.

Acute cluster headache treatments

Fast-acting cluster headache medications available from your doctor include:

• Oxygen. Briefly inhaling 100 percent oxygen through a mask at a minimum rate of at least 12 liters a minute provides dramatic relief for most who use it. The effects of this safe, inexpensive procedure can be felt within 15 minutes. Oxygen is generally safe and without side effects. The major drawback of oxygen is the need to carry an oxygen cylinder and regulator with you, which can make the treatment inconvenient and inaccessible at times. Small, portable units are available, but some people still find them impractical.
• Triptans. The injectable form of sumatriptan (Imitrex), which is commonly used to treat migraine, is also an effective treatment for acute cluster headache. The first injection may be given while under medical observation. Some people may benefit from using sumatriptan in nasal spray form, but for most people this isn’t as effective as an injection and it may take longer to work. Sumatriptan isn’t recommended if you have uncontrolled high blood pressure or heart disease.
• Another triptan medication, zolmitriptan (Zomig), can be taken in nasal spray or tablet form for relief of cluster headache. This medication may be an option if you can’t tolerate other forms of fast-acting treatments.
• Octreotide. Octreotide (Sandostatin), an injectable synthetic version of the brain hormone somatostatin, is an effective treatment for cluster headache for some people.
• Local anesthetics. The numbing effect of local anesthetics, such as lidocaine (Xylocaine), may be effective against cluster headache pain in some people when given through the nose (intranasal).
• Dihydroergotamine. The injectable form of dihydroergotamine (D.H.E. 45) may be an effective pain reliever for some people with cluster headache. This medication is also available in an inhaled (intranasal) form called Migranal, but this form hasn’t been proved to be effective for cluster headache.

Preventive cluster headache treatments

Preventive therapy starts at the onset of the cluster episode with the goal of suppressing attacks.

Determining which medicine to use often depends on the length and regularity of your episodes. Under the guidance of your doctor, the drugs can be tapered off once the expected length of the cluster episode ends.

Cluster headache preventive medication

• Calcium channel blockers. The calcium channel blocking agent verapamil (Calan, Verelan, others) is often the first choice for preventing cluster headache. Verapamil may be used with other medications. Occasionally, longer term use is needed to manage chronic cluster headache. Side effects may include constipation, nausea, fatigue, swelling of the ankles and low blood pressure.
• Corticosteroids. Inflammation-suppressing drugs called corticosteroids, such as prednisone, are fast-acting preventive medications that may be effective for many people with cluster headaches. Your doctor may prescribe corticosteroids if your cluster headache condition has started recently or if you have a pattern of brief cluster periods and long remissions. Although corticosteroids might be a good option to use for several days, serious side effects such as diabetes, hypertension and cataracts make them inappropriate for long-term use.
• Lithium carbonate. Lithium carbonate, which is used to treat bipolar disorder, may be effective in preventing chronic cluster headache if other medications haven’t prevented cluster headaches. Side effects include tremor, increased thirst and diarrhea. Your doctor can adjust the dosage to minimize side effects. While you’re taking this medication, your blood will be checked regularly for the development of more-serious side effects, such as kidney damage.
• Nerve block. Injecting a numbing agent (anesthetic) and corticosteroid into the area around the occipital nerve, situated at the back of your head, might improve chronic cluster headaches. An occipital nerve block may be useful for temporary relief until long-term preventive medications take effect.
• Melatonin. Studies in small numbers of people suggest that 10 milligrams of melatonin taken in the evening might reduce the frequency of cluster headache.
• Other preventive medications used for cluster headache include anti-seizure medications, such as topiramate (Topamax, Qudexy XR).

Cluster headache Surgery

Rarely, doctors may recommend surgery for people with chronic cluster headaches who don’t find relief with aggressive treatment or who can’t tolerate the medications or their side effects.

Several small studies found that occipital nerve stimulation on one or both sides may be beneficial. This involves implanting an electrode next to one or both occipital nerves.

Deep brain stimulation is a promising but as yet unproven treatment for cluster headaches that don’t respond to other treatments. Because this involves placing an electrode deep in the brain, there are significant risks, such as an infection or hemorrhage.

Some surgical procedures for cluster headache attempt to damage the nerve pathways thought to be responsible for pain, most commonly the trigeminal nerve that serves the area behind and around your eye.

However, the long-term benefits of destructive procedures are disputed. Also, because of the possible complications — including muscle weakness in your jaw or sensory loss in certain areas of your face and head — it’s rarely considered.

Potential future cluster headache treatments

Researchers are studying a potential treatment called occipital nerve stimulation. In this procedure, your surgeon implants electrodes in the back of your head and connects them to a small pacemaker-like device (generator). The electrodes send impulses to stimulate the area of the occipital nerve, which may block or relieve your pain signals.

Several small studies of occipital nerve stimulation found that the procedure reduced pain in some people with chronic cluster headaches.

Similar research is underway with deep brain stimulation. In this procedure, doctors implant an electrode in the hypothalamus, the area of your brain associated with the timing of cluster periods. Your surgeon connects the electrode to a generator that changes your brain’s electrical impulses and may help relieve your pain.

Deep brain stimulation of the hypothalamus may provide relief for people with severe, chronic cluster headaches that haven’t been successfully treated with medications.

Cluster headache home remedies

The following measures may help you avoid a cluster attack during a cluster cycle:

• Maintaining a regular sleep schedule. Cluster periods can begin when there are changes in your normal sleep schedule. During a cluster period, follow your usual sleep routine.
• Avoid alcohol. Alcohol consumption, including beer and wine, can quickly trigger a headache during a cluster period.
• Taking medication as prescribed.
• Avoiding high stress or strenuous physical activity
• Avoiding high altitude
• Quit smoking.

1. The International Classification of Headache Disorders, 3rd edition (beta version). Headache Classification Committee of the International Headache Society (IHS). Cephalalgia Vol 33, Issue 9, pp. 629 – 808. First Published June 14, 2013 https://doi.org/10.1177/0333102413485658[↩]
2. Leroux E, Ducros A. Cluster headache. Orphanet Journal of Rare Diseases. 2008;3:20. doi:10.1186/1750-1172-3-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517059/[↩]