In addition to the sharp pain, people suffering from a cluster attack often have puffiness under the eyes, watering of the eyes, drooping of the eyelids, constriction of the pupils and a runny nose. Each cluster attack can last anywhere from 15 minutes to 3 hours and can occur up to eight times a day. The attacks occur in groups and can last for weeks or months. After this period of attacks, a person may remain cluster free for months or years. Chronic cluster headaches occur for more than one year without going away or only being gone less than two weeks.
Cluster headaches can occur in either sex at any age, but are more prevalent among men.
Although not all causes of cluster headaches are known, alcoholic beverages are known to bring them on during a period of attacks. Furthermore, patients describe a seasonal relationship to the beginning of a series of attacks. Other than these two triggers, the actual cause of the headaches is undetermined. Many specialists recommend the person suffering from cluster headaches keep a journal. By recording when the attacks occur, how long they last and what he or she did in the days before and during the attack, the sufferer may be able to determine what events or factors contributed to the attacks and may be able to avoid these things.