Cluster Headache Symptoms
Cluster headache presents with severe, strictly unilateral orbital, supraorbital, or temporal pain lasting 15-180 minutes, accompanied by ipsilateral cranial autonomic features and restlessness, occurring with a frequency of one to eight attacks per day. 1
Core Pain Characteristics
The headache pain itself has distinct features that differentiate it from other primary headache disorders:
- Severity and location: The pain is severe to very severe in intensity and strictly unilateral, affecting the orbital, supraorbital, and/or temporal regions 2, 3
- Duration: Individual attacks last between 15 and 180 minutes when untreated 1, 4
- Frequency: Attacks occur from once every other day up to eight times per day 1, 5
- Quality: Patients describe the pain as excruciating, with female patients reporting each attack as worse than childbirth 2
Ipsilateral Cranial Autonomic Symptoms
At least one of the following autonomic features must be present on the same side as the pain 1:
- Lacrimation (tearing) - most common autonomic symptom 5
- Conjunctival injection (red eye) - very common 5
- Nasal congestion 1
- Rhinorrhea (runny nose) 1, 3
- Forehead and/or facial sweating 1
- Ptosis (drooping eyelid) 1, 5
- Miosis (pupil constriction) 1, 5
- Eyelid edema (swelling) 1, 5
Behavioral Features
A distinguishing characteristic of cluster headache is the sense of restlessness or agitation during attacks, which contrasts sharply with migraine patients who typically prefer to remain still 3, 6, 5. This restlessness is so characteristic that patients often pace, rock, or cannot sit still during attacks 6.
Diagnostic Requirements
Five attacks meeting the above criteria are required for diagnosis 1. The International Headache Society criteria specify that patients must have experienced at least five attacks with the characteristic pain, duration, frequency, and at least one ipsilateral autonomic symptom 1.
Common Pitfalls in Recognition
- Misdiagnosis as migraine or trigeminal neuralgia is common, leading to diagnostic delays typically lasting years 4, 3
- Patients often initially present to otolaryngologists or dentists rather than neurologists due to the facial location of symptoms 6
- The bilateral presentation mentioned in older guidelines 1 is actually incorrect; cluster headache is strictly unilateral according to current understanding 7, 2, 3
Pattern Recognition
- Episodic cluster headache (80% of cases) occurs in bouts or cluster periods lasting weeks to months, separated by remission periods of at least three months 4, 5
- Chronic cluster headache has remission periods lasting less than three months 4
- Attacks often follow circadian and circannual rhythms, with many patients experiencing attacks at predictable times of day or during specific seasons 6, 8
Common Triggers
Specific triggers that can precipitate attacks include 5, 8:
- Alcohol consumption (most common trigger during cluster periods)
- Nitroglycerin
- Foods containing nitrates
- Strong odors or perfumes