Cluster headaches occur in cyclical patterns or clusters, which gives the condition its name. Cluster headache is one of the most painful types of headache.
Cluster headache commonly awakens you in the middle of the night with intense pain in or around one eye on one side of your head.
Bouts of frequent attacks, known as cluster periods, may last from weeks to months, usually followed by remission periods when the headache attacks stop completely. During remission, no headaches occur for months and sometimes even years.
Fortunately, cluster headache is rare and not life-threatening. Treatments can help make cluster headache attacks shorter and less severe. In addition, medications can help reduce the number of cluster headaches.
Common signs and symptoms
The pain of a cluster headache is often described as sharp, penetrating or burning. People with this condition say that the pain feels like a hot poker being stuck in the eye or that the eye is being pushed out of its socket.
People with cluster headache appear restless. They may pace or sit through the attack. In contrast to people with migraine, people with cluster headache usually avoid lying down during an attack because this position seems to increase the pain.
Some migraine-like symptoms — including nausea, sensitivity to light and sound, and aura — may occur with a cluster headache, though usually on one side.
Cluster period characteristics
Most people have episodic cluster headaches. In episodic cluster headaches, the cluster headaches occur for one week to a year, followed by a pain-free remission period that may last as long as 12 months before another cluster headache develops.
Chronic cluster periods may continue for more than a year, or pain-free periods may last less than one month.
During a cluster period:
The pain usually ends as suddenly as it begins, with rapidly decreasing intensity. After attacks, most people are completely free from pain, but exhausted.
When to see a doctor
Headache pain, even when severe, usually isn't the result of an underlying disease, but headaches may occasionally indicate a serious underlying medical condition, such as a brain tumor or rupture of a weakened blood vessel (aneurysm).
Additionally, if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.
Seek emergency care if you have any of these signs and symptoms:
The exact cause of cluster headaches is unknown, but abnormalities in the hypothalamus likely play a role. Cluster attacks usually occur with clocklike regularity during a 24-hour day, and the cycle of cluster periods often follows the seasons of the year.
These patterns suggest that the body's biological clock is involved. In humans, the biological clock is located in the hypothalamus, which lies deep in the center of your brain.
Abnormalities of the hypothalamus may explain the timing and cyclical nature of cluster headache. Imaging studies have detected increased activity in the hypothalamus during the course of a cluster headache.
Unlike migraine and tension headache, cluster headache generally isn't associated with triggers, such as foods, hormonal changes or stress. Some people experience an aura or nausea similar to those experienced with migraine headaches.
Once a cluster period begins, however, consumption of alcohol can quickly trigger a splitting headache. For this reason, many people with cluster headache avoid alcohol for the duration of a cluster period.
Other possible triggers include the use of medications such as nitroglycerin, a drug used to treat heart disease.
Risk factors for cluster headaches include:
Preparing for your appointment
You're likely to start by seeing your family doctor. However, you may be referred to a neurologist, a doctor trained in treating brain and nervous system disorders, such as headache.
Because appointments can be brief, and there's often a lot to talk about, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, as well as what to expect from your doctor.
Keep a headache diary
Your time with your doctor is limited, so preparing a list of questions may help you make the most of your time together. List your questions from most important to least important in case time runs out. For cluster headaches, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.
What to expect from your doctor
Tests and diagnosis
Cluster headache has a characteristic type of pain and pattern of attacks. A diagnosis depends on your description of the attacks, including your pain, the location and severity of your headaches, and associated symptoms. The frequency and duration of your headaches also are important factors.
If you have chronic or recurrent headaches, your doctor may try to pinpoint the type and cause of your headache using certain approaches.
Treatments and drugs
There's no cure for cluster headaches. The goal of treatment is to decrease the severity of pain, shorten the headache period and prevent the attacks.
Because the pain of a cluster headache comes on suddenly and may subside within a short time, cluster headache can be difficult to evaluate and treat, as it requires fast-acting medications.
Some types of acute medication can provide some pain relief quickly. Based on the latest studies, the therapies listed below have proved to be most effective for acute and preventive treatment of cluster headache.
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.
Other preventive medications used for cluster headache include anti-seizure medications such as divalproex (Depakote) and topiramate (Topamax).
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 surgery 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.
Research in potential 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 other medications.
Researchers are studying other types of brain and nerve stimulation to prevent and treat cluster headaches.
Lifestyle and home remedies
The following measures may help you avoid a cluster attack during a cluster cycle:
Because cluster headaches can be so painful, you may be tempted to try alternative or complementary therapies to relieve your pain.
A survey of people with cluster headache who tried a number of alternative therapies — including acupuncture, acupressure, therapeutic touch, chiropractic and homeopathy — found that fewer than 10 percent thought these therapies effective.
Some natural medicines may be worth a try, however. In one study, extract from kudzu, a vine species originally found in Asian countries, was shown to alleviate the intensity, frequency and duration of cluster headache attacks. However, kudzu extract didn't decrease the length of the cluster cycle.
Melatonin also has shown modest effectiveness in treating nighttime attacks.
Coping and support
Living with cluster headache can be very difficult. Cluster headaches can be frightening to you and to your family and friends. The debilitating attacks may seem unbearable.
In addition to the physical symptoms, the chronic pain that often accompanies cluster headache attacks can make you anxious or depressed. Ultimately, it may affect your interaction with friends and family, your productivity at work, and the overall quality of your life.
Talking to a counselor or therapist can help you cope with the effects of cluster headache. Or you may find encouragement and understanding in a headache support group. Although support groups aren't for everyone, they can be good sources of information.
You may also find support groups are a good place for you to share your experiences and hear other group members' experiences. If you're interested, your doctor may be able to recommend a group in your area.
Because the cause of cluster headache is unknown, you can't prevent a first occurrence. However, a preventive strategy is crucial for managing cluster headache because only trying to treat acute attacks with medications can seem hopeless.
Prevention can help reduce the frequency and severity of the cluster attacks and the risk of medication overuse headaches. Preventive medications can also increase the effectiveness of acute medications.
In addition, you may help reduce your risk of future attacks by avoiding alcohol and nicotine, which often cause cluster headaches.
Last Updated: 2013-06-04
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