Headache Hub: Condition guide
Cluster headache: symptoms, criteria, and tracking
Cluster headache is one of the most severe primary headache disorders, and one of the most frequently mistaken for something else. This guide covers what it feels like, the ICHD-3 criteria specialists use, and how tracking your attacks with Ember builds a history your doctor can act on.
- ICHD-3 code 3.1
- About 0.1% prevalence
- Attacks last 15 to 180 minutes
The condition
What is cluster headache?
Excruciating, strictly one-sided pain around the eye, temple, or forehead, arriving in clusters that last weeks or months, followed by remission periods. Attacks bring prominent same-side autonomic symptoms such as tearing, nasal congestion, and eyelid drooping.
Key characteristics
- Excruciating, strictly one-sided pain, usually around the eye or temple
- Short attacks of 15 to 180 minutes, often recurring at the same time of day
- Autonomic symptoms on the same side: tearing, red eye, nasal congestion, eyelid drooping
- Restlessness or agitation during attacks, unlike the stillness of migraine
Prevalence and demographics
- Global prevalence
- About 0.1% of the population
- Gender ratio
- 2-3:1 male to female
- Typical onset
- 20 to 40 years of age
- Misdiagnosis
- Common, often mistaken for migraine
The clinical standard
ICHD-3 diagnostic criteria for cluster headache
Specialists diagnose cluster headache (ICHD-3 code 3.1) against four criteria. Ember organizes what you report using the same framework, so your history maps onto what your clinician needs.
Criterion A
At least 5 attacks
Fulfilling criteria B through D.
Criterion B
Pain characteristics
Severe, strictly unilateral orbital, supraorbital or temporal pain lasting 15 to 180 minutes when untreated.
Criterion C
Associated symptoms (at least one, same side)
Lacrimation, conjunctival injection, nasal congestion, rhinorrhoea, forehead or facial sweating, miosis, ptosis, eyelid oedema, or a sense of restlessness and agitation.
Criterion D
Attack frequency
From one attack every other day up to 8 attacks per day during a cluster period.
How tracking helps
Pattern capture
Cluster attacks have a distinctive rhythm. Ember records the timing, side, and autonomic features of each attack as you describe them in your own words.
ICHD-3 aware
Your entries are organized against the same diagnostic framework specialists use, so nothing clinically relevant gets lost.
A clearer differential
A structured attack history helps your clinician distinguish cluster headache from migraine and other look-alikes faster.
Ember is free to start and available around the clock. It helps you track and organize your headache history; it does not diagnose, and it never replaces evaluation by a clinician.
Why it matters
Why recognizing cluster headache early is critical
Getting the right name on this condition changes what treatment is even on the table.
Extreme pain
Cluster headache is sometimes called suicide headache because of its severity. Recognizing it early matters for getting effective care.
High misdiagnosis rate
It is often mistaken for migraine or sinus problems, which can delay access to the treatments that actually work for cluster headache.
Specific treatments
Unlike other headaches, cluster headache responds to specific therapies such as high-flow oxygen, so correct identification by a clinician is vital.
When to seek emergency care: a headache that reaches maximum intensity within seconds to a minute, or any worst-ever headache, is a medical emergency. Seek immediate medical care rather than an online resource.
Do not suffer in silence
Describing your attacks to Ember takes minutes. It captures the pattern, organizes it against ICHD-3, and gives you a structured history to bring to your doctor, so the visit starts at the decision instead of the recall.
Start with EmberQuestions
Frequently asked questions about cluster headache
Keep reading
Related headache disorders
Migraine
Often confused with cluster headache, but with distinct pain quality, duration, and accompanying symptoms.
Read the guideTrigeminal autonomic cephalalgias (TACs)
Cluster headache belongs to this group of severe one-sided headaches, alongside paroxysmal hemicrania and SUNCT.
Guide coming soon
Headache Hub
Explore all the primary headache disorder guides, anchored to ICHD-3.
Back to the hubNext step
Severe, one-sided, and on a schedule? Track it.
Do not let an unnamed pattern delay your care. Ember turns your attacks into a structured history you and your doctor can act on.