Migraines are believed to be a neurovascular disorder with evidence supporting its mechanisms starting within the brain and then spreading to the blood vessels. Migraine begins by neuronal changes leading to the activation of the brainstem and diencephalic nuclei and subsequent dilatation of the large cranial and proximal intracranial vessels.  Some researchers feel neuronal mechanisms play a greater role, while others feel blood vessels play the key role. Others feel both are likely important. High levels of the neurotransmitter serotonin, also known as 5-hydroxytryptamine, are believed to be involved.
Migraine pathophysiology
Glaucoma pathophysiology
Migraine risk factors
Temporal arteritis laboratory findings
Migraine laboratory findings
Cavernous sinus thrombosis pathophysiology
Transient ischemic attack pathophysiology
Cerebral venous sinus thrombosis pathophysiology