• Clinical science

Cluster headache


Cluster headache (CH) is a type of primary headache that mostly affects adult men. Patients present with recurrent, fifteen minute up to three hour attacks of agonizing, strictly unilateral headaches in the periorbital and forehead region (areas innervated by the trigeminal nerve). These attacks are associated with ipsilateral symptoms of increased cranial autonomic activity, e.g., lacrimation, conjunctival injection, rhinorrhea, or partial Horner syndrome. Cluster headaches tend to occur in episodic patterns (“cluster bouts”) followed by months of remission, but are considered chronic if remission between bouts lasts less than one month. Diagnosis is based on the patient's history, in particular on the exact description and timing of the headaches. Acute episodes are treated with 100% oxygen or triptans, while verapamil is used for preventative treatment.


  • Sex: > (3:1)
  • Peak incidence: 20–40 years


Epidemiological data refers to the US, unless otherwise specified.


  • Not entirely understood
  • Risk factor: tobacco use
  • Possible triggers: alcohol, histamine, seasonal fluctuations


Clinical features

  • Headache characteristics
    • Agonizing pain
    • Strictly unilateral, periorbital, and/or temporal
    • Short, recurring attacks; that usually occur in a cyclical pattern (“clusters”)
      • May become chronic (less common), with interruptions of less than one month between cluster bouts
      • Attacks often wake patients up during sleep.
  • Ipsilateral autonomic symptoms
  • Restlessness and agitation

While patients with migraine headaches tend to rest motionlessly in a quiet, dark room, individuals with cluster headache pace around restlessly in excruciating pain!



  • Based on patient history and physical examination
  • Rule out any suspected underlying disease
    • Neuroimaging
    • Doppler ultrasound


Differential diagnoses

  • See learning card on “Headache for more information regarding differential diagnoses.

The differential diagnoses listed here are not exhaustive.


Medical therapy

Interventional therapy

Interventional procedures (e.g., ablative injections, deep brain stimulation) may be considered in patients with cluster headache who do not respond to medical therapy.