International Headache Society diagnoses a migraine by its pain and number of attacks (at least 5, lasting 4-72 hours if untreated), and additional symptoms including nausea and/or vomiting, or sensitivity to both light and sound. Migraine is three times more common in women than in men and affects more than 10 percent of people worldwide. Roughly one-third of affected individuals can predict the onset of a migraine because it is preceded by an “aura,” visual disturbances that appear as flashing lights, zig-zag lines or a temporary loss of vision. People with migraine tend to have recurring attacks triggered by a number of different factors, including stress, anxiety, hormonal changes, bright or flashing lights, lack of food or sleep, and dietary substances. Migraine in some women may relate to changes in hormones and hormonal levels during their menstrual cycle.
A cluster headache is one-sided head pain that may involve tearing of the eyes and a stuffy nose. Attacks occur regularly for 1 week to 1 year, separated by long pain-free periods that last at least 1 month, possibly longer. Cluster headaches are a fairly common form of chronic, repeated headaches. They are four times more common in men than women. The headaches can occur at any age but are most common in adolescence and middle age. They tend to run in families, passed down through genes. Scientists do not know exactly what causes cluster headaches, but they appear to be related to the body’s sudden release of histamine or serotonin. A problem in a small area at the base of the brain called the hypothalamus may be involved.