Cluster headache
| 3.1 Diagnostic criteria: |
| A At least five attacks fulfilling B–D |
| B Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15–180 minutes 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) Forehead and facial sweating |
| (4) Ipsilateral eyelid oedema |
| (5) Ipsilateral forehead and facial sweating |
| (6) Ipsilateral miosis and/or ptosis |
| (7) A sense of restlessness or agitation |
| D Attacks have a frequency from one every other day to eight per day |
| E Not attributed to another disorder |
| 3.1.1 Episodic cluster headache |
| Description: Occurs in periods lasting seven days to one year separated by pain free periods lasting one month or more |
| Diagnostic criteria: |
| A All fulfilling criteria A–E of 3.1 |
| B At least two cluster periods lasting from 7 to 365 days and separated by pain free remissions of one month or more |
| 3.1.2 Chronic cluster headache |
| Description: Attacks occur for more than one year without remission or with remissions lasting less than one month |
| Diagnostic criteria: |
| A All alphabetical headings of 3.1 |
| B Attacks recur for more than one year without remission periods or with remission periods lasting less than one month |