Paroxysmal hemicrania are attacks with pain characteristics very similar to those of cluster headache. cluster headache and with similar accompanying signs and symptoms, but with shorter duration, higher frequency of attacks, higher prevalence in females and absolute response to indomethacin.

The pain attacks are unilateral, of severe or very severe intensity, in the orbital, supraorbital and/or temporal region, with a duration of 2 to 30 minutes. The headache is associated with at least one of the following signs that must be present on the same side of the pain:

  • Conjunctival injection and/or lacrimation.
  • Nasal obstruction and/or rhinorrhea.
  • Palpebral edema.
  • Sweating of the face and forehead.
  • Myosis and/or ptosis.

The frequency of attacks is more than 5 per day for more than half the time, although there may be periods of lower frequency.