Cluster headache symptoms

The pain

The defining symptom of cluster headache is severe, one-sided pain centred around, behind or above one eye - almost always on the same side for any given patient. The pain builds rapidly from nothing to peak intensity, typically within 5–10 minutes of onset. At its peak it is typically rated 9–10 out of 10 (often described as 10/10).

Patients commonly describe the pain as a burning, stabbing, boring or drilling sensation - as if a hot poker or an ice pick is being driven into the eye or the side of the head. The pain can radiate to the temple, cheek, jaw, neck and shoulder on the same side.

An attack lasts between 15 minutes and 3 hours, most commonly 45–90 minutes. After the attack, there is typically a sudden and complete end to the pain, often leaving the patient exhausted. There is usually not the post-attack fatigue ("headache hangover") that some migraine patients experience.

Autonomic symptoms - the eye and nasal features

On the same side as the pain, most patients experience one or more of the following:

Not all patients have all autonomic symptoms, and the presence and severity of these features can vary between attacks in the same patient. However, at least one autonomic symptom on the same side as the pain is present in the vast majority of cluster headache attacks and is one of the key diagnostic criteria.

Agitation and restlessness

Unlike migraine, where patients typically seek a dark, quiet room and try to lie still, cluster headache patients are usually extremely restless during an attack. Pacing, rocking, banging the head, pressing on the eye - these are common responses to the pain.

This agitation is not a psychological response - it reflects the neurological nature of the attack. Lying still often makes the pain feel worse, while movement can feel very slightly less unbearable. This distinguishing feature is important for diagnosis: if a patient tells you they have to pace during their attacks, migraine is less likely and cluster headache should be considered.

Timing and pattern of attacks

Attacks are characteristically time-locked - they tend to occur at the same time or times each day. Many patients have attacks that wake them from sleep, typically 1–2 hours after falling asleep. This "alarm clock" pattern reflects the hypothalamic (circadian) component of cluster headache.

During a cluster period, most patients have 1–3 attacks per day, though up to 8 per day is possible in severe cases. Attacks are always one-sided, and in most patients always on the same side (though about 15% of patients experience side-switching between periods).

A warning sign some patients notice

Some patients notice a very brief prodrome - a mild discomfort, pressure or heaviness on the affected side - in the minutes before an attack begins. Recognising this warning can give a small window of time to start oxygen treatment before the pain peaks.

What a cluster period looks like

During an active cluster period, attacks occur daily (or multiple times daily) for weeks to months - typically 4–12 weeks for episodic cluster headache. Between cluster periods, most patients have no attacks at all. The cluster period often starts and ends relatively abruptly.

For chronic cluster headache patients (approximately 15% of people with the condition), there is no meaningful remission period - attacks continue for more than 12 months without remission, or with remissions lasting less than three months.