Typical pattern

• Sudden, extreme burning, stabbing, or boring pain on one side of the head
• Usually lasts 15 minutes to 3 hours
• Occurs up to several times daily, often at nearly the same time each day or overnight
• Attacks come in “clusters” lasting weeks to months, separated by headache-free periods
• During an attack, people are often restless or pace rather than lie still

Same-side symptoms

• Tearing or red eye
• Blocked or runny nostril
• Drooping eyelid or a smaller pupil
• Facial sweating or flushing
• Eyelid swelling

Treatment

• High-flow 100% oxygen, via a non-rebreather mask, is a first-line attack treatment.
• Subcutaneous sumatriptan is another fast option. Nasal sumatriptan or zolmitriptan may be used when injections are unsuitable.
• Prevention during a cluster period commonly involves verapamil, prescribed and monitored by a clinician. Other options may include a short corticosteroid bridge, lithium, topiramate, or specialist therapies depending on episodic versus chronic disease. The Mayo Clinic treatment overview summarizes these approaches.

When to seek urgent care

Acute treatment: stop each attack quickly

1. 100% oxygen
   • Use a non-rebreather mask at 10 to 15 L/min for 15 to 20 minutes while sitting upright.
   • This is first-line for many people and can be repeated for subsequent attacks.
   • Never smoke or use flames near oxygen.
2. Sumatriptan 6 mg subcutaneous injection
   • The most rapid drug treatment and appropriate when oxygen is unavailable, insufficient, or in combination with it.
   • Common maximum is 12 mg in 24 hours, separated by at least 1 hour.
   • Avoid or seek specialist advice with known coronary/cerebrovascular disease, uncontrolled hypertension, or certain vascular conditions.
3. If injection is unsuitable
   • Sumatriptan nasal spray 20 mg or zolmitriptan nasal spray 5 mg may help, though they tend to act less rapidly than an injection.
   • Non-invasive vagus nerve stimulation is another specialist-prescribed option, particularly for episodic cluster headache.

Preventive treatment: suppress attacks throughout the cluster period

1. First-line long-term preventive: verapamil

• Usually the preferred preventive treatment for both episodic and chronic cluster headache.
• It is started at a low dose and increased gradually, commonly toward a total daily dose in the 240 to 960 mg/day range, depending on response and tolerability.
• It requires a baseline ECG and repeat ECGs with dose increases because it can slow cardiac conduction and cause heart block. The specialist guidance on verapamil monitoring emphasizes this requirement.
• Do not self-start, increase, or stop verapamil.

2. Transitional treatment: while verapamil begins working

• Oral corticosteroid, such as prednisone/prednisolone, followed by a taper
• Or a greater occipital nerve block with local anesthetic plus corticosteroid, usually performed by a headache specialist

3. Alternatives or add-on preventives

• Galcanezumab 300 mg subcutaneously monthly: an option for episodic cluster headache where locally approved/available.
• Lithium: particularly considered for chronic cluster headache. It requires serum lithium, kidney function, and thyroid monitoring.
• Topiramate: another alternative, but cognitive effects, mood symptoms, weight loss, and kidney stones can limit use.
• Melatonin: sometimes used as an adjunct, typically at night.
• Non-invasive vagus nerve stimulation: may be used for prevention in some specialist pathways.

Practical plan for a person with confirmed cluster headache

• Keep high-flow oxygen and/or prescribed sumatriptan injection accessible at home, work, and when travelling.
• Start or contact the prescriber promptly at the beginning of a cluster period to initiate prevention.
• Keep a diary of attack time, side, duration, triggers, acute treatments, and response.
• Avoid alcohol completely during an active cluster bout, since it commonly triggers attacks. Maintain regular sleep timing.
• See a neurologist or headache specialist, especially for first presentation, chronic cluster headache, atypical symptoms, poor response, cardiovascular disease, pregnancy, or suspected medication contraindications.