Clinical Education Resource

Could It Be Cluster?

One of the most painful conditions known to medicine — and one of the most frequently misdiagnosed.

Cluster headache is often mistaken for migraine, sinusitis, or dental pain. The result: years of ineffective treatment and unnecessary suffering. This resource helps clinicians recognize the hallmarks and act.

Review Diagnostic Criteria Symptoms & Presentation

7 years

Average time to correct diagnosis

Bahra et al., Cephalalgia 2002

≥77%

Of patients initially misdiagnosed

Rozen & Fishman, Headache 2012

KSS 9–10

Pain intensity on Kiel Cluster Scale — exceeds childbirth

ICHD-3 Classification

ICHD-3 Aligned

Recognizing the Presentation

Cluster headache has a distinctive clinical signature. ICHD-3 criteria require at least one ipsilateral autonomic feature.

Anatomical diagram showing unilateral orbital and temporal pain distribution in cluster headache

Pain localizes to orbital, supraorbital, and temporal regions — always unilateral

Severe to very severe unilateral orbital, supraorbital, or temporal pain
Attack duration 15–180 minutes (untreated)
Frequency: 1 every other day to 8 per day
Ipsilateral conjunctival injection and/or lacrimation
Ipsilateral nasal congestion and/or rhinorrhea
Ipsilateral eyelid edema
Ipsilateral forehead and facial sweating
Ipsilateral miosis and/or ptosis
Sense of restlessness or agitation — patient cannot lie still

The restlessness criterion is a key differentiator from migraine, where patients typically prefer to lie still in a dark room.

Full Symptoms & Presentation

Differential Diagnosis

Common Misdiagnoses

Understanding why cluster headache is missed helps clinicians ask the right questions.

Often confused with

Migraine

Cluster attacks are shorter (15–180 min vs. 4–72 hr), strictly unilateral, and accompanied by agitation rather than photophobia-driven stillness.

Often confused with

Sinusitis

Autonomic features (lacrimation, rhinorrhea) mimic sinus symptoms, but cluster pain is periorbital and episodic — not pressure-like or positional.

Often confused with

Trigeminal Neuralgia

TN pain is lancinating and triggered by touch; cluster pain is deep, boring, and spontaneous. TN attacks last seconds, not minutes.

Often confused with

Dental Pain

Upper molar and jaw pain can mimic cluster. Key: cluster attacks are strictly time-limited, recur in bouts, and resolve completely between periods.

Full Differential Diagnosis Guide

Clinical Decision Support

Think it could be cluster?

Use the ICHD-3 criteria checklist to evaluate your patient's presentation. Early recognition changes outcomes.

View Diagnostic Criteria