Overview

Cluster headache is a very painful type of headache. It usually occurs in periods of frequent attacks known as clusters. Cluster headaches can wake people from sleep. These headaches cause intense pain in or around one eye on one side of the head.

Cluster periods can last from weeks to months. Then usually the headaches stop for a period of time, which may last for months or years.

Cluster headache is rare. Treatments can shorten cluster headache attacks and lessen the pain. Also, medicines can reduce the number of cluster headaches.

Symptoms

Common symptoms

A cluster headache strikes quickly. There's usually no warning. But some people might first have migraine-like nausea and aura. Common symptoms during a cluster headache include:

• Extreme sharp or stabbing pain, usually in, behind or around one eye. The pain can spread to other areas of the face, head and neck.
• Pain on one side of the head in a single cluster. Pain can switch to the other side in another cluster.
• Restlessness.
• A lot of tears.
• Redness of the eye on the side that hurts.
• Stuffy or runny nose on the side that hurts.
• Forehead or facial sweating.
• Skin color changes on the side of the face that hurts.
• Swelling around the eye on the side that hurts.
• Drooping eyelid on the side that hurts.

Because the pain of a cluster headache can be so bad, those who have one are likely to pace or sit and rock back and forth.

Cluster periods

A cluster period usually lasts for several weeks to months. Each cluster period may start at about the same time of year and last about the same length of time. For example, cluster periods can come during certain seasons, such as every spring or every fall.

For most people with cluster headaches, the cluster period lasts from one week to a year. Then there's a pain-free period, known as remission, for three months or longer before the next cluster headache comes. This is known as episodic cluster headache.

Cluster periods might go on for more than a year. Pain-free periods might last less than one month. If a cluster period lasts a year without letup, it's called chronic cluster headache.

During a cluster period:

• Headaches usually come every day, often several times a day.
• A single attack can last from 15 minutes to three hours, but more often lasts 30 to 45 minutes.
• The attacks often occur at the same time each day.
• Most attacks occur at night, usually 1 to 2 hours after bedtime.

The pain usually ends as suddenly as it begins. After attacks, most people are pain-free but exhausted.

When to see a doctor

See a health care provider if you've just started to have cluster headaches. Your provider can rule out other illnesses and suggest treatment.

Even bad headache pain isn't usually the result of another disease. But headaches can sometimes mean a serious medical condition. This can include a brain tumor or tear of a weakened blood vessel, known as a dissection.

Also, if you have a history of headaches, see your health care provider if there's a change in how they feel or how often they occur.

Seek emergency care if you have any of these symptoms:

• A severe headache that comes on all of a sudden, often like a clap of thunder.
• A headache with a fever, nausea or vomiting, a stiff neck, confusion, seizures, numbness, or trouble speaking. These might point to a stroke, meningitis, encephalitis, a brain tumor or other problems.
• A headache after a head injury, especially if it gets worse — even if the injury was a minor fall or bump.
• A sudden, severe headache unlike any other.
• A headache that worsens over days and changes in pattern.

Causes

Experts don't know what causes cluster headache. Cluster headache patterns suggest a link to the area of the brain that helps run the body's biological clock, known as the hypothalamus.

Cluster headache triggers

There are several cluster headache triggers. The most common is drinking alcohol. Other triggers might include weather changes and certain medicines.

Risk factors

Risk factors for cluster headache include:

• Sex. Men are more likely to have cluster headaches than women are.
• Age. Most people who develop cluster headaches are between ages 20 and 50. But the condition can start at any age.
• Smoking. Many people who get cluster headaches are smokers. But quitting smoking usually doesn't stop the headaches.
• Alcohol use. If you have cluster headaches, drinking alcohol during a cluster period may increase the risk of an attack.
• Family history. Having a parent, brother or sister who has cluster headache might increase the risk.

Diagnosis

Cluster headache has a certain type of pain and pattern of attacks. A diagnosis depends on describing the pain, where the pain is, how bad it is and other symptoms. How often headaches come and how long they last also are important.

For cluster headache, a specialist trained in treating headaches (neurologist) makes a diagnosis on medical history, symptoms, and a physical and neurological examination.

For people with unusual or complicated headaches, tests to rule out other causes for the pain might include:

• An MRI scan. A magnetic resonance imaging (MRI) scan uses a powerful magnetic field and radio waves to produce detailed images of the brain and blood vessels. MRI scans help diagnose tumors, strokes, bleeding in the brain, infections, and other brain and nervous system conditions. Conditions that affect the brain and nervous system are also known as neurological conditions.
• A CT scan. A computerized tomography (CT) scan uses a series of X-rays to create detailed cross-sectional images of the brain. This helps diagnose tumors, infections, brain damage, bleeding in the brain and other possible medical problems that may be causing headaches.

Treatment

There's no cure for cluster headaches. The goal of treatment is to decrease the pain, shorten the headache period and prevent new attacks.

Because the pain of a cluster headache tends to come on suddenly and go away quickly, it can be hard to treat. Treatment requires fast-acting medicines.

Fast-acting treatments

These treatments aim to stop a cluster headache once it's begun:

• Oxygen. Breathing in pure oxygen through a mask provides relief for most who use it. People feel the effects of this safe treatment within 15 minutes.

  Oxygen generally has no side effects. But it's not used for people with severe chronic obstructive pulmonary disease.

• Triptans. Sumatriptan (Imitrex) is given as a shot when cluster headache symptoms start. Using sumatriptan as a nasal spray or using another triptan medicine, zolmitriptan (Zomig), also has been shown to work, but not as quickly as a shot.

  Sumatriptan isn't recommended for people who have uncontrolled high blood pressure or heart disease.

  Shots and nose sprays are used more often than oral medicines because they act faster than medicines taken by mouth do.

• Octreotide. Octreotide (Sandostatin), a shot of a version of the brain hormone somatostatin, works for some people with cluster headache. It might be used for people for whom triptans don't work well.
• Local anesthetics. The numbing effect of local anesthetics, such as lidocaine, might work against cluster headache pain in some people when given through the nose.
• Dihydroergotamine. A form of dihydroergotamine given through a vein might help relieve pain for some people with cluster headache. This medicine also comes in a form that's inhaled through the nose. But this form hasn't been proved to work for cluster headache.

Preventive treatments

Preventive therapy starts at the onset of the cluster period with the goal of stopping the attacks. Once the bout of cluster headache ends, a health care provider helps you gradually stop taking the medicine.

• Calcium channel blockers. The calcium channel blocking agent verapamil (Calan SR, Verelan) is often the first choice for preventing cluster headache. Verapamil might be used with other medicines. Sometimes, longer term use is needed to manage chronic cluster headache.

  Most people can take verapamil without problems. But side effects might include constipation, nausea, tiredness and irregular heartbeat.

• Corticosteroids. These medicines, such as prednisone (Prednisone Intensol, Rayos), act fast to relieve cluster headaches. They might be used for people who don't have cluster headache often and whose bouts are brief.

  These medicines might be useful for relief until long-term medicines start to work. They're often used with verapamil.

  Corticosteroids might be good to use for several days. But they can cause serious side effects if used long-term. Side effects can include diabetes, high blood pressure and osteoporosis.

• Galcanezumab (Emgality). The Food and Drug Administration recently approved this medicine for the treatment of episodic cluster headache. It's given as a monthly shot until the cluster period ends.

• Lithium (Lithobid). This medicine is used to treat bipolar disorder. It might help prevent long-lasting, known as chronic, cluster headache. It's used for people who can't take other medicines or for whom other medicines haven't worked.

  Side effects include tremor, increased thirst and kidney problems. Taking this medicine means having regular bloodwork and other tests to check for serious side effects.

• Noninvasive vagus nerve stimulation (VNS). Noninvasive VNS uses a hand-held controller to send electrical stimulation to the vagus nerve through the skin. Although more research is needed, some studies have found that VNS helped reduce the frequency of cluster headaches.

• Nerve block. This involves a shot of pain-relieving medicine into the back of the head. The medicine goes into an area around a nerve known as the occipital nerve. The shot might include a numbing medicine, known as an anesthetic, and a corticosteroid.

  An occipital nerve block might be useful for relief until long-term medicines start to work. It's often used in combination with verapamil.

Other preventive medicines used for cluster headache include anti-seizure medicines, such as topiramate (Topamax, Qudexy XR).

Surgery

Rarely, surgery might help people with chronic cluster headaches who don't get relief from other treatments.

Some surgeries for cluster headache try to damage the nerve pathways thought to cause the pain.

However, the long-term benefits of these surgeries are uncertain, and complications can be serious. They include muscle weakness in the jaw and loss of feeling in parts of the face and head.

Potential future treatments

Researchers are studying other ways of treating cluster headache, including a number of procedures that stimulate nerves. These include sphenopalatine ganglion stimulation, occipital nerve stimulation and deep brain stimulation.

These procedures involve placing a device in certain areas of the brain that can send an electrical signal to the area to block pain. These procedures have shown promise in treating cluster headache. More study is needed.

Lifestyle and home remedies

To avoid a cluster headache attack during a cluster period, try the following:

• Stick to a regular sleep schedule. During a cluster period, don't change when and how long you sleep. Sleep changes can trigger cluster headaches.
• Avoid alcohol. Drinking alcohol, including beer and wine, can trigger a headache during a cluster period.

Alternative medicine

A hormone, melatonin, that affects the body's clock might help in relieving cluster headache attacks. A chemical from chili peppers, capsaicin, used inside the nose, might reduce how often cluster headache attacks occur and how bad they are. Talk to your health care provider before using any alternative treatments.

Coping and support

Living with cluster headache can be hard. Having cluster headache attacks can affect relationships, work and quality of life.

Talking to a counselor or therapist might help. A headache support group can help you get support and information. Your health care provider might be able to suggest a therapist or a support group in your area.

Preparing for an appointment

You're likely to start by seeing your primary care provider. However, you may be referred to a neurologist.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do before it, such as fasting for certain tests.

Keep a headache diary

One of the most helpful things you can do is keep a headache diary. Each time you get a headache, note these details that will give your health care provider information to help with diagnosis:

• Date. Charting the date and time of each headache can help you see patterns.
• Duration. How long does each headache last?
• Intensity. Rate your headache pain on a scale from 1 to 10, with 10 being the worst.
• Triggers. List possible triggers that might have caused your headache, such as certain foods, sounds, odors, physical activity or sleeping too much.
• Symptoms. Did you have symptoms before the headache, such as aura?
• Medicines. List all medicines, vitamins and supplements you take, including doses.
• Relief. Have you had any pain relief? How much or how little?

Take a family member or friend to your appointment, if possible, to help you remember the information you get.

List questions to ask your doctor. For cluster headaches, basic questions include:

• What's likely causing my symptoms?
• What other possible causes are there?
• What tests do I need?
• Is my condition likely to go away or be long-lasting?
• What treatment do you recommend?
• I have other health conditions. How can I best manage them together?
• Are there restrictions I need to follow?
• Should I see a specialist?
• Are there brochures or other printed material I can have? What websites do you recommend?

Be sure to ask all the questions you have.

What to expect from your doctor

Your doctor is likely to ask you questions, such as:

• When did your symptoms begin?
• Do you have symptoms sometimes or all the time?
• Do your symptoms tend to occur at the same time of day? Do they occur during the same season each year?
• Does alcohol appear to cause your symptoms?
• How bad are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?