A group of headaches distinct from migraine and tension-type headaches.

• Cluster headaches: produce intense pain episodically. Symptoms are severe unilateral orbital (eye) pain lasting 15 min to 3 hr, ipsilateral autonomic symptoms such as lacrimation (tears) and nasal congestion/discharge.
• Short-lasting neuralgiform headaches: rare, severe and brief pain that occurs on one side of the head. SUNCT are associated with ipsilateral conjunctival tearing, while SUNA are also associated with nasal congestion/discharge.
• Paroxysmal hemicrania: rare, severe brief pain occurring on one side of the head, orbitofrontally.