In short
Cluster headache causes attacks of extremely severe pain around or behind one eye, lasting 15 minutes to three hours, with a red, watering eye and blocked or runny nose on the same side. Attacks come in bouts lasting weeks to months, often at the same time each day. Effective treatments exist, so getting the diagnosis right matters.
On this page
What is cluster headache?
Cluster headache is a rare but extremely painful primary headache disorder. It affects about one in 1,000 people and is more common in men. It often starts between the ages of 20 and 40. It’s sometimes described as one of the most painful conditions known.
Symptoms of an attack
- Excruciating pain around or behind one eye, or at the temple, always on the same side during a bout
- Attacks lasting 15 minutes to three hours
- On the same side: a red, watering eye, a blocked or runny nostril, a drooping eyelid or small pupil, facial sweating or flushing
- Restlessness and agitation: people often pace, rock or can’t keep still, unlike migraine, where people usually lie still
- From one attack every other day to eight a day
Headaches taking whole days away?
Talk it through with an Australian doctor online. No referral needed.
Bouts and clockwork timing
Most people have episodic cluster headache: attacks happen daily for a period of weeks to months (a cluster bout), then stop for months or years. Bouts often come at the same time of year, and attacks often come at the same time of day or night, commonly waking people from sleep. A smaller number have chronic cluster headache with little or no break.
Triggers
- Alcohol during a bout, often within an hour
- Strong smells, such as solvents or perfume
- Napping or disrupted sleep
Cluster headache is more common in people who smoke.
Headache behind the left eye
Severe pain behind one eye with a red, watery eye and runny nose on the same side is typical of cluster headache. But pain behind an eye has other causes too, some urgent. See headache behind the eyes.
Diagnosis and treatment
Diagnosis is based on the pattern of attacks, using international criteria. Doctors often arrange a brain scan the first time, to rule out other causes. Treatment has two parts:
- Treating attacks: specific treatments work quickly. Everyday pain relief tablets act too slowly to help.
- Prevention: treatment during a bout to reduce or stop attacks.
A review in The Lancet Neurology describes several effective options. A GP can start treatment and refer you to a neurologist.
When to get urgent help
Call 000 for a first-ever sudden severe headache, headache with weakness, confusion or loss of vision, or a red, painful eye with blurred vision and vomiting, which can be acute glaucoma.
Next step: talk to a doctor
Answer a few quick questions and you’ll get an email about your eligibility. A consultation doesn’t guarantee any particular treatment.
References
- Hoffmann J, May A. Diagnosis, pathophysiology, and management of cluster headache. Lancet Neurol. 2018;17(1):75-83.
- . Headache Classification Committee of the International Headache Society (IHS) The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38(1):1-211.
- Robbins MS. Diagnosis and Management of Headache: A Review. JAMA. 2021;325(18):1874-1885.
- Migraine & Headache Australia. Migraine & Headache Australia.
This guide is general information, not medical advice. It doesn’t replace a consultation with a doctor who knows your history. In an emergency, call 000.