Older theories suggested that blood vessels narrowed and/or widened, which started migraine pain and other symptoms. Now many headache researchers realize that blood vessels do not initiate the pain, but may contribute to it.
Current thinking regarding migraine pain has moved more toward the source of the problem, as improved technology and research has paved the way for a better understanding. Today it is widely understood that chemical compounds and hormones, such as serotonin and estrogen, often play a role in pain sensitivity for migraine sufferers.
One aspect of migraine pain theory explains that migraine pain occurs due to waves of activity by groups of excitable brain cells, which trigger chemicals, such as serotonin to constrict blood vessels. Serotonin is a chemical necessary for communication between nerve cells. It can cause constriction of blood vessels.
When serotonin or estrogen levels change, the result for some is a migraine. Serotonin levels may affect both sexes, while fluctuating estrogen levels affect women only.
For women, who experience more migraines than men, estrogen levels naturally vary over the life cycle, with increases during fertile years and decreases afterwards. Women of child bearing age also have monthly changes in estrogen levels. Migraines in women are often associated with these fluctuating hormone levels.
Some researchers suggest that when estrogen levels decline it may trigger contractions in blood vessels, leading to throbbing pain. Others suggest that lower levels of estrogen make facial and scalp nerves more sensitive.
What commonly triggers a migraine?
People who get migraines may be able to identify triggers that seem to start the onset of symptoms. Some possible triggers include the following:
Stress and other emotions
Biological and environmental conditions, such as hormonal shifts or exposure to light