Cluster headache is among the most severe pain in clinical medicine, and it is routinely misdiagnosed as migraine or sinus disease for years before anyone names it.
How it presents
Strictly one-sided pain, centred in or behind the eye or over the temple. It reaches full intensity within minutes and lasts between about fifteen minutes and three hours untreated. On the painful side there is usually at least one autonomic sign: a watering or reddened eye, a drooping or swollen eyelid, a blocked or running nostril, facial sweating, or a constricted pupil.
The behaviour is distinctive. Migraine makes people lie still in the dark; cluster makes them pace, rock, or press something hard against the eye. Attacks run in bouts — daily or several times daily for weeks to months, then remission — and they have a strong tendency to strike at the same time each day and to wake people from sleep.
The physician who treats you has had them since he was seventeen
Dr. Padda has lived with chronic cluster headache since the age of 17, and spent years inside the cycle before finding a way out of it. You will not have to convince anyone here that a headache can be this bad, or that “suicide headache” is a name the condition earned rather than an exaggeration. Read more.
Oxygen first
High-flow normobaric oxygen — 100% oxygen through a non-rebreather mask for fifteen to twenty minutes — is a first-line abortive and should be the backbone of treatment for almost everyone with cluster headache. It works quickly, it has essentially no systemic side effects, there is no limit on how often it can be used, and it does not interact with anything.
Two things commonly go wrong. The first is flow rate: a nasal cannula at two or three litres a minute does not reproduce the effect, and most people who tell us oxygen failed were never given a proper non-rebreather setup. The second is access — an abortive treatment is close to useless if you have to drive somewhere to get it. Part of what we do is get a home oxygen setup in place so you can treat the attack in the first minutes.
What else helps
- Greater occipital nerve block with a corticosteroid can interrupt a bout, and is often used as a bridge while a preventive medication is titrated to an effective dose.
- Sphenopalatine ganglion block targets the autonomic relay responsible for the tearing and congestion. No needle, no sedation.
- Preventive medication to shorten the bout, started as soon as a bout is recognised rather than after weeks of attacks.
Why it gets missed
The autonomic signs — blocked nose, watering eye, facial pain — read as sinusitis, and people are treated with antibiotics and decongestants through bout after bout. The strict one-sidedness and the clock-like timing are the features that break the tie. If you have had repeated courses of antibiotics for “sinus headaches” that always affect the same side and always start at the same hour, that history is worth bringing in.