(See also Overview of Headache.)
Because of their similarities, SUNCT and cluster headaches are often grouped together as trigeminal autonomic cephalgias. Trigeminal autonomic cephalgias also include chronic paroxysmal hemicrania, and hemicrania continua—all very rare disorders.
Usually, pain occurs around the eye on one side of the head. People may have up to 200 bouts of pain a day, and the pain may last from 5 seconds to over 4 minutes. The affected eye is red (called conjunctival injection) and frequently waters (tears).
Doctors diagnose SUNCT based on symptoms. Magnetic resonance imaging (MRI) is done to rule out other causes.