Cluster headache period characteristics include: A cluster period may stick around for several weeks to months. The beginning date and the length of each cluster period may or may not be consistent from period to period. Research finds that cluster periods may occur seasonally, such as every spring season or every fall. A lot of individuals have episodic cluster headaches. In these cases, the headaches occur for one week to a year, followed by a pain-free remission time frame that may last as long as 12 months before the next cluster headache develops. Chronic cluster periods are known to continue for over a year; pain-free intervals could last less than one month. Commonly, cluster headaches occur seasonally, typically in spring or in fall. A single attack can last from 15 minutes to three hours. DH attacks often occur at the same time each day. Most attacks occur at night, usually one to two hours after you go to bed. They usually occur just a few hours after people fall asleep as well, and you may miss getting enough sleep. Not only are they incredibly painful, but they also inhibit your natural sleep patterns. The pain usually ends as abruptly as it came on, with rapidly decreasing intensity. After attacks, most people are pain-free but exhausted.