Cluster headaches affect one side of the head (unilateral) and may be associated with tearing of the eyes and nasal congestion. They occur in clusters, happening repeadedly ever day at the same time for several weeks and then remitting. Cluster headaches are a fairly common form of chronic, recurrent headache. Unlike migraines, they affect men more often than women. They affect people of any age but are common between adolescence and middle age. There does not seem to be a pattern among families in the development of cluster headaches. Cluster headaches occur as a severe, sudden headache. The onset is sudden, and it occurs most commonly during the dreaming (REM) phase of sleep. Cluster headache may occur daily for months, alternating with periods without headaches (episodic), or they can occur for a year or more without stoping (chornic). A person may experience alternating chronic and episodic phases.
Symptoms: Swelling under or around the eyes, red eye (on affected side), flushed face, excessive tears, runny nose or nasal congestion. The pain commonly begins 2 to 3 hours after falling asleep and is steady, sharp, or burning. It characteristically occurs on one side of the head and may occur in and around one eye. It may involve one side of the face fron neck temples. Pain quickly gets worse, peaking within 5 to 10 minutes and peak may last one-half to 2 hours.