6 Signs Your Headache Is a Cluster Headache, Not a Severe Migraine

Migraine pain typically builds over 20 to 30 minutes or longer. Cluster headache pain does not build, it strikes and reaches its worst intensity within five to ten minutes of onset. The speed of arrival is one of the most reliable distinguishing features a neurologist will ask about. If you can mark the exact minute it started, that pattern is worth telling your doctor.




Cluster headache pain is strictly one-sided and centres on or behind one eye, sometimes radiating into the temple or upper jaw on the same side. Migraine can also be one-sided, but it commonly shifts sides between episodes or spreads across the forehead. In cluster headache, the side is consistent within a cluster period and the eye is almost always involved. A throbbing or boring sensation that sits squarely behind one eye, episode after episode, is a signal worth raising with a neurologist.


This is the feature that most reliably separates cluster headache from migraine. During a cluster attack, the autonomic nervous system produces visible changes on the same side as the pain: the eye reddens and waters, the eyelid droops slightly, the pupil may constrict, and the nostril on that side runs or blocks. These are not symptoms of crying or of a cold, they appear at the same moment the pain does and resolve when it does. Migraine can cause light sensitivity and nausea, but it does not routinely produce this cluster of one-sided eye and nose signs. If a doctor asks whether your eye waters during the headache, the answer to that question has diagnostic weight.




A migraine episode typically lasts 4 to 72 hours. Cluster headache attacks are shorter, the International Headache Society defines them as lasting 15 minutes to 3 hours. Many people with cluster headache report attacks of 45 minutes to 90 minutes that end as abruptly as they started. If your severe one-sided headache reliably resolves within two hours, that duration pattern is clinically meaningful and should be part of what you tell your doctor.

Cluster headaches are named for their pattern: multiple attacks per day for weeks or months, followed by a remission period that can last months or years. During a cluster period, attacks often occur at the same time each day, frequently in the early hours of the morning, which has led researchers to link them to circadian rhythm disruption. Migraine episodes are also recurrent, but they do not follow this tight cyclical pattern of active periods and long remissions. If your severe headaches arrive in concentrated bursts for six weeks and then vanish for a year, that cycle is the clearest single indicator of cluster headache.

Migraine pain is typically worsened by movement. Most people with migraine lie down in a dark room and stay still. People in a cluster attack do the opposite, they pace, rock, press their fist against the eye, or sit hunched forward. This agitation is a recognised feature of cluster headache and reflects the intensity and character of the pain rather than a behavioural choice. If someone who witnesses your attacks notices that you cannot keep still, mention it. It is a clinically useful observation.

These six signs do not add up to a diagnosis, that requires a neurologist, a detailed headache history, and in some cases imaging to rule out other causes of severe one-sided head pain. What they do is give you a more precise account of what is happening, which makes the clinical conversation more productive. Cluster headache is significantly underdiagnosed, partly because people assume any severe headache is migraine. The two conditions have different treatment pathways, and the difference in outcome when the right one is identified early is substantial.