Hormonal changes in women

Fluctuations in estrogen seem to trigger headaches in many women with known migraines. Women with a history of migraines often report headaches immediately before or during their periods, when they have a major drop in estrogen. Others have an increased tendency to develop migraines during pregnancy or menopause. Hormonal medications — such as oral contraceptives and hormone replacement therapy — also may worsen migraines, though some women find it's beneficial to take them.

Brain chemicals - serotonin

Serotonin is a type of neurotransmitter, or "communication chemical" which passes messages between nerve cells. It helps to control mood, pain sensation, sexual behaviour and sleep, as well as dilation and constriction of the blood vessels, among other things. Low serotonin levels in the brain may lead to a process of constriction and dilation of the blood vessels which trigger a migraine. Serotonergic agonists, such as triptans, LSD or psilocin, activate serotonin receptors to stop a migraine attack.

Imbalances in brain chemicals, including serotonin — which helps regulate pain in the nervous system — may be the cause of migraines.

Serotonin levels drop during migraine attacks. This may trigger our trigeminal system to release substances called neuropeptides, which travel to the brain's outer covering (meninges). The result is headache pain.