Cluster headaches occur in cyclical patterns or clusters, which gives the condition its name. Cluster headache is one of the most painful types of headache.
Cluster headache commonly awakens you in the middle of the night with intense pain in or around one eye on one side of your head.
Bouts of frequent attacks, known as cluster periods, may last from weeks to months, usually followed by remission periods when the headache attacks stop completely. During remission, no headaches occur for months and sometimes even years.
Fortunately, cluster headache is rare and not life-threatening. Treatments can help make cluster headache attacks shorter and less severe. In addition, medications can help reduce the number of cluster headaches.