An Overview of Cluster Headaches

Cluster headaches are characterized by sudden bouts of recurrent, severe headaches that occur every day (or nearly every day) for weeks, months, or even years. Pain associated with this condition—which is so severe, the disorder is sometimes called “suicide headache”—tends to localize on one side of the head and is often accompanied by red or inflamed eyes as well as discharges from the nose. In most cases, there are periods of remission with no attacks that last anywhere from months to years.

This type of headache is relatively rare (it happens in between 0.1 and 0.3 percent of the population), but it occurs most often in those between 20 and 40 years old. Furthermore, men are twice as likely to experience it.

The most common of a group of disorders called “trigeminal autonomic cephalalgias,” cluster headaches arise as severe pain in one side of the head, usually starting off around one eye, before spreading to the temples and face. The intensity of this pain is described as a very severe burning, poking, or piercing (as opposed to throbbing). This may be accompanied by one of a number of additional symptoms, including: 

• Flushed face and sweating
• Redness and inflammation in the affected eye
• Tearing
• Drooping of the affected eyelid
• Extreme constriction of the pupil 
• Runny or stuffed up nose
• Facial swelling
• Restlessness and inability to sit still or lie down

The duration of the headache is usually 15 to 30 minutes; however, it can last for up to three hours. Attacks tend to group together, and patients experience anywhere from one to eight periods of pain a day. Cluster headaches tend to occur at consistent times of day—oftentimes at night—and are often seasonal, more commonly arising in the spring or fall. These cluster cycles are punctuated by periods of remission, which can last anywhere from less than a month to several years. 

As with other primary headache disorders, the exact cause of cluster headache is unknown. However, researchers have observed increased activity in the hypothalamus brain region, which is associated with regulating sleep-wake cycles and biological rhythm, so there’s increasing evidence that a problem here is leading to attacks. The direct cause of headache is the dilation of vessels putting pressure on the trigeminal nerve, a nerve associated with facial sensation as well as movement.

While triggers aren’t as prevalent with cluster headaches as with migraine or other types, but certain behaviors are known to set off this kind of headache. There are a number of risk factors for the condition:

• Smoking tobacco
• Alcohol consumption
• Age between 20 to 40
• Men are twice as likely as women to develop the condition
• Family history

Proper diagnosis of this condition isn’t easy as there’s no singular test for it. What’s even more challenging is that cluster headache can easily be mistaken for migraine. Still, diagnostic criteria are established by the International Classification of Headache Disorders. Basically, a patient is determined to have it if he or she experiences at least five attacks characterized by one of the following:

• Severe pain on one side of the head
• Headache accompanied by at least one of the other symptoms of the condition
• A frequency of attack of one every other day to up to eight a day

Taking on cluster headache is usually an individualized process, and what works for one person may not for another. Broadly speaking, treatments can be divided into acute approaches for attacks after onset, and those that are preventative in nature. The former of these approaches include:

• Oxygen: A common approach taken on in the hospital involves delivering pure oxygen via mask with a tank. When treated this way, dramatic reductions in symptoms are seen within 15 minutes.
• Triptans: Administration of this class of pharmaceutical drug is a common treatment for both cluster and migraine headache. The drug sumatriptan is especially effective in taking on attacks when injected in the hospital, while also being effective delivered in a nasal spray form. In addition, another type, zolmitriptan, is available as a nasal spray. 
• Octreotide: The idea behind the injection of octreotide is that it mimics the brain chemical somatostatin. While generally not as effective as triptans, this approach works very well in some cases.
• Local Anesthetic: Local anesthetics such as lidocaine, usually delivered through the nose, can also put a stop to pain.  
• Dihydroergotamine: Another medication that’s also used in migraine treatment, dihydroergotamine, when injected, is known to be effective in taking on symptoms.  

There are also a number of preventative approaches to this condition; these are to be applied shortly after the onset of headache:

• Calcium Channel Blockers: Stopping calcium from entering the bloodstream prevents vessels help ease pressure in the veins. As such, calcium channel blocking drugs like Calan, Veralan, and others are part of a preferred approach to taking on headache. They're often administered alongside other medications. 
• Corticosteroids: This class of drug is especially effective in reducing inflammation and can be very effective in taking on symptoms. Prednisone, for instance, is often indicated and known to be a fast-acting, preventative approach.   
• Lithium Carbonate: A common approach to treating bipolar disorders, lithium carbonate may be indicated when other drugs have not yielded desired results.
• Nerve Block: The targeted delivery of local anesthetic combined with a corticosteroid in the area around the occipital nerve (towards the back of the head) is sometimes used to combat difficult, chronic cases.
• Emgality: In 2019, the FDA approved the injection of a migraine preventing medication—Emgality—to take on cluster headache. 

In chronic cluster headache cases—or in those where medications simply aren’t doing the job—surgeries or other medical treatments may be required. The stimulation of certain brain regions, for instance, can help reduce headache pain. This involves the use of electrodes called neurostimulators in either the sphenopalatine ganglion (a cluster of nerves linked to the trigeminal nerve often at the core of pain) or the vagus nerve in the neck. Though effective, these approaches are invasive and have a chance of side effects. 

The fact that headaches aren’t visible makes it difficult for family, friends, and coworkers of sufferers to understand the severity of what they’re experiencing. The severity of cluster headache can affect work performance, for instance, and may make fulltime hours temporarily impossible. This being the case, it’s a good idea for those with this condition to be open and informative about the condition with managers and colleagues.  

A Word From Verywell

At the end of the day, the intensity and severity of cluster headache should not be underestimated. Because there’s a perception that this pain is just incidental and not an actual disorder, it may be dismissed by friends, family, and coworkers. If you suffer from this condition, be sure to push back against attempts to dismiss how you feel and how you’re affected by this issue. Most importantly, though, don’t suffer in silence; treatments and approaches are available. Your health is important, and you owe it to yourself and those around you to get help when you need it.