Cluster headaches are typically very short in duration, excruciating headaches, usually felt on one side of the head behind the eyes. Cluster headaches affect about 1 million people in the United States. They are also often misdiagnosed as migraines. This is the only type of headache that tends to occur at night. The term cluster is utilized because the headaches occur is groups or clusters within specific time frames. The time frames vary from five minutes to several hours. Patients experience several headaches a day for many weeks followed by a period of time without headaches. Most people who suffer from this form of a headache will begin to experience symptoms at about 25 years of age. Men are affected five times more frequently than women.
Symptoms are usually described as pain on one side with stabbing eye pain that usually begins just after the patient goes to sleep. The eye on the affected side will usually tear excessively during the headaches. Constriction of the pupil is common. Some patients report nasal stuffiness and runny nose on the affected side. Pain from the headache is carried through the nerve that provides sensation to the face (the trigiminal nerve). When activated, it will trigger severe eye pain, though pain in the forehead, temple, nose, cheek or upper gum can has also been reported. The scalp may also become tender to the touch. Pain can be quite intense. The cause of most cluster headaches is unknown.
Chiropractic manipulation of the cervical and thoracic spine areas has been shown to relieve signs and symptoms of cluster headaches. Since the cause of these headaches is unknown, the reason manipulation helps is not completely clear.