Cluster Headache
Cluster headache is the most common trigeminal autonomic cephalalgia and a primary headache disorder, meaning it is not caused by another underlying condition.
This updated UKMLA guide to cluster headache is based on NICE CG150, which covers causes, risk factors, symptoms, diagnosis, and management.
Causes and Risk Factors
The exact cause and underlying pathophysiology of cluster headache are complex and not well understood
- It is thought to involve hypothalamic dysregulation, trigeminal pain pathways and cranial autonomic activation
Risk factors:
- More common in males
- Family history (esp. 1st degree relative with cluster headache)
Environmental factors may trigger an acute attack:
- Alcohol
- Smoking
- Histamine
- Nitrate-containing food (e.g. cured meat)
- Smell of volatile substances (e.g. petrol, paint, perfume, nail varnish)
Headache Red Flags
If the headache has ANY of the following red flags, consider the need for further investigations and/or referral:
| Category | Red Flag | Explanation |
|---|---|---|
| Infection / inflammation | Worsening headache with fever | Suggests possible central nervous system infection (e.g., meningitis, encephalitis) or inflammatory disease. |
| Symptoms suggestive of giant cell arteritis (e.g., jaw claudication, age >50, visual symptoms) | Points to vasculitis with risk of vision loss or stroke. | |
| Immunocompromised status (HIV, immunosuppressive drugs) | Increases risk for opportunistic infections and neoplastic processes. | |
| Vascular / haemorrhagic | Sudden-onset headache reaching maximum intensity within 5 minutes (thunderclap) | Characteristic of subarachnoid haemorrhage, reversible cerebral vasoconstriction syndrome, or other acute vascular events. |
| New-onset neurological deficit | May indicate stroke, intracranial mass, encephalitis, or other structural or metabolic brain disorders. | |
| New cognitive dysfunction, personality change, or impaired level of consciousness | Suggests stroke, intracranial mass, encephalitis, or other significant brain pathology. | |
| Raised ICP / structural | Headache triggered by cough, valsalva manoeuvre, sneeze, or exercise | Can be a sign of increased intracranial pressure (e.g., due to intracranial mass). |
| Vomiting without other clear cause | May reflect increased intracranial pressure or mass effect. | |
| Substantial change in headache characteristics | May signal a new secondary process, such as neoplasm or infection. | |
| Intracranial hypotension | Typical of intracranial hypotension, often due to CSF leak. | |
| Trauma-related | Recent head trauma (within 3 months) | Raises concern for traumatic intracranial haemorrhage (e.g. subdural haematoma). |
| Oncology-related | Age <20 with history of malignancy | Raises suspicion for metastatic or recurrent disease affecting the CNS. |
| History of malignancy known to metastasise to the brain | Increases risk for intracranial metastases. | |
| Ophthalmic emergencies | Symptoms/signs of acute narrow-angle glaucoma (painful red eye, visual loss) | Requires urgent ophthalmological evaluation. |
If there is a new-onset headache with ANY of the following, consider the need for further investigations and/or referral:
- Immunocompromised (e.g. HIV, use of immunosuppressive drugs)
- <20 y/o + history of malignancy
- History of malignancy known to metastasise to the brain
- Vomiting without other obvious causes
Clinical Features and Diagnosis
Cluster headache, like other primary headache disorders, is primarily a clinical diagnosis.
Consider using a headache diary for at least 8 weeks to help diagnose primary headaches. The patient should record the following:
- Frequency, duration and severity of headaches
- Any associated symptoms
- Possible precipitants
- Relationship of headaches to menstruation
- All medications taken to relieve headaches
Do NOT refer people diagnosed with tension‑type headache, migraine, cluster headache or medication-overuse headache for neuroimaging solely for reassurance.
Typical clinical features of cluster headache (at least 5 episodes of the following):
- Severe or very severe, unilateral headache (orbital, supraorbital and/or temporal pain), and
- Duration: 15 min-3 hours (if untreated), and
- Sense of restlessness or agitation (typically walking up and down, pacing, clutching the affected side)
- Ipsilateral autonomic features:
- Conjunctival injection and/or lacrimation
- Eyelid swelling
- Miosis and/or ptosis (partial Horner’s syndrome)
- Nasal congestion and/or rhinorrhoea
- Forehead and facial sweating
- Forehead and facial flushing
- Sensation of fullness in the ear
- The attacks may wake the person from sleep, about 1.5–2 hours after falling asleep
Cluster headache attacks occur in series, usually lasting 2 weeks-3 months (cluster periods or ’bouts’)
Trigeminal Autonomic Cephalalgias
Cluster headache is the most common trigeminal autonomic cephalalgia – a group of primary headache disorders characterised by unilateral trigeminal-distribution head/facial pain with ipsilateral cranial autonomic features.
| Disorder | Classic clinical patterns |
|---|---|
| Cluster headache |
|
| Paroxysmal hemicrania | Similar to cluster headache but attacks are shorter and more frequent
|
| SUNCT / SUNA |
|
| Hemicrania continua |
|
Management
Acute Management
- Short-burst oxygen therapy (100% oxygen at >12 L/min with a non-rebreathing mask), AND/OR
- Home and ambulatory oxygen can be arranged if attacks are recurrent and the diagnosis is clear
- Subcutaneous or nasal triptan (sumatriptan injection or zolmitriptan intranasal spray)
- Only for adults>18 y/o
- Do not offer oral triptans
Discuss the need for neuroimaging for first bout of cluster headache with a specialist.
Triptan is contraindicated in the presence of cardiovascular disorders, previous TIA / CVA, and severe hepatic impairment.
Do not offer paracetamol, NSAIDs, opioids or ergots for acute cluster headache
Prophylactic Management
- Assess for and manage any underlying triggers or associated conditions (e.g. alcohol, smoking, diet, stress, anxiety, mood disorder)
- Consider verapamil for prophylaxis
References