A cluster headache is a form of intense head pain that affects one side of the head or around one eye, often with tearing and redness of the eye and a stuffy or runny nose. Skin may be pale and sweaty, and the pain, which is usually described as an excruciating, often burning sensation, may spread to the neck or shoulders.
The attacks may occur cyclically several times within a week or over longer periods, giving them the name ‘cluster’ as they tend to come in clusters, or cycles.
Cluster headaches are among the most painful one can experience, reports the Mayo Clinic. They come on quickly, often during the night; pain lasts anywhere from a few minutes to three or more hours. Cluster headaches can also occur during daytime and usually happen around the same time of night or day.
Repeating episodes of headaches can last for several weeks or months. This is usually followed by periods of remission that can last for months or even years with no episodes. Migraine-like symptoms may also accompany cluster headache, with auras, sensitivity to sound and light and nausea, although usually just on the affected side.
The causes of cluster headache
According to the National Center for Biotechnology Information tobacco smoke and alcohol may be triggers for cluster headaches, although unlike migraine and other forms of headache, most cluster headaches aren’t believed to be set off by food sensitivities, stress or hormonal fluctuations.
Abnormalities of the hypothalamus are thought to be responsible for the fact that attacks come on with clock-like regularity, adds the Mayo Clinic. Images of brain scans taken during cluster headache episodes show heightened activity of the hypothalamus during the attacks.
Diagnosing cluster headaches
An MRI test may be required to distinguish cluster headaches from other kinds and causes of pain. If you are experiencing an attack during the examination, the physician should be able to note the presence of Horner syndrome: a drooping eyelid or small pupil on one side. As these changes aren’t normally seen outside of a cluster headache, and are the only obvious neurological signs, this can be a strong indicator of cluster headache diagnosis.
Danger signs relating to cluster headaches
Cluster headaches by themselves are not considered life-threatening nor do they cause permanent brain changes. They can impact your work and personal life, and are considered a chronic condition. There are other serious conditions with similar symptoms, such as brain tumor or ruptured blood vessels, which may be present. Contact your health care provider immediately if you experience any of the following:
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Drowsiness
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Nausea or vomiting
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Changes in vision
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Changes in sensation, alertness or movement
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Occurrence of seizures
Medication for cluster headache
While medications can’t completely stop the headaches, they can help you to have more control over the pain and return to your normal activities.
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Triptans, such as sumatriptan (Imitrex).
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Cyproheptadine
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Anti-inflammatory medicines, including steroid prednisone injections
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Various blood pressure medicines, such as propranolol or similar beta-blockers or calcium channel blockers including verapamil
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Injections of dihydroergotamine (DHE), which quickly stops cluster headaches but may be dangerous if taken with sumatriptan
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Anti-seizure medicine, such as valproic acid and topiramate
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Antidepressants, including amitriptyline
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Melantonin – 10 milligrams taken before bedtime may reduce the frequency of attacks
As a rule, over-the-counter (OTC) painkillers and narcotics do not have much effect on cluster headaches, unlike other forms of headache or migraine.
Preventing cluster headache
You may need to work with your health care provider to find which medication works best. Some medications can help prevent more frequent occurrences but will probably not end them altogether. Many people find that avoiding alcohol and smoking helps to reduce the frequency and severity of attacks. While many medications may prolong the 
Image Source: Simone Capretti
