Cluster headaches are relatively rare, and they are one of the few types of headaches that affect men more often than women.
What causes cluster headaches?
The cause of cluster headaches is unknown. They may be genetic, since people whose parents or siblings have cluster headaches are at more risk for developing them.
Cluster headaches may be caused by a problem in an area of the brain called the hypothalamus. This area of the brain seems to be more active in people who have cluster headaches.
If you are prone to cluster headaches, certain triggers may cause a headache or make one worse. These triggers often include alcohol; sleep apnea (regularly stopping breathing during sleep); stress; or fatigue.
What are the symptoms?
Symptoms include burning or sharp, piercing pain on one side of your head. The pain radiates around the temple and eye, with the affected eye becoming red, watery, or puffy. The eyelid may droop, and you may have a runny or stuffy nose on the affected side.
The pain usually intensifies quickly—within 5 to 10 minutes of onset—and may last for around 30 minutes to several hours. These headaches may begin at night, within 2 to 3 hours of falling asleep. They may start while you are dreaming, but they can occur at any time. Cluster headaches can continue for days, weeks, or months before you stop having symptoms (remission). You may not have another cycle of cluster headaches for months or years. Less commonly, your headaches may become chronic and continuous.
How are cluster headaches diagnosed?
Cluster headaches are diagnosed with a medical history and physical examination. Your health professional will usually be able to identify cluster headaches from your description of the type and location of pain, duration and pattern of headaches, and how frequently the headaches occur.
Imaging tests (such as a CT scan or an MRI) are not usually needed to help find a treatment for your pain. Your doctor may order imaging tests to rule out other conditions, especially if the pattern of your pain is not typical of cluster headaches. Most headaches are not caused by life-threatening medical conditions and do not need imaging tests.
How are they treated?
Although there is no cure for cluster headaches, treatment may reduce the frequency of headaches, severity of pain, and possibly shorten the duration of each cycle of headaches (also called a cluster period). You may take medicine every day during a cluster period to prevent headaches (prophylactic headache medicines, such as verapamil). This type of medicine may help reduce the frequency or severity of cluster headaches within a cluster period. Medicines to stop a headache (abortive headache medicines, such as sumatriptan) may be used to stop a headache after it has started. These medicines are not taken daily to prevent headaches.
Another effective treatment is high-flow oxygen. Breathing in pure oxygen relieves cluster headache pain almost immediately—within 10 to 20 minutes—for many people who have cluster headaches.
You also may reduce the frequency of cluster headaches during a cluster period by avoiding alcohol, not smoking, reducing stress, and maintaining a regular sleep schedule.
Last Updated:
April 11, 2008
