Table 12 Classification of cluster headache [1]

3.1 [G44.0/N90] Cluster headache

 A. At least five attacks fulfilling criteria B–D

 B. Severe unilateral orbital, supraorbital and/or temporal pain lasting from 15 to 180 min if untreated

 C. Headache is accompanied by at least one of the following:

  1. Ipsilateral conjunctival injection and/or lacrimation

  2. Ipsilateral nasal congestion and/or rhinorrhoea

  3. Ipsilateral oedema of the eyelid

  4. Ipsilateral forehead and facial perspiration

  5. Ipsilateral miosis and/or ptosis

  6. A sense of restlessness or agitation

 D. Attacks have a frequency from once every other day to eight per day

 E. Not attributed to another disorder

3.1. [G43.01/N89] Episodic cluster headache

 A. Attacks fulfilling criteria A–E for 3.1 cluster headache

 B. At least two cluster periods lasting 7–365 days and separated by attack-free periods of ≥1 month

3.1.2 [G43.02/N89] Chronic cluster headache

 A. Attacks fulfilling criteria A–E for 3.1 cluster headache

 B. Attacks recur over >1 year without or with remission periods lasting >1 month