Despite migraine being described for thousands of years, the pathophysiology of this disorder is still not completely understood. Migraine is a form of sensory dysfunction, with many manifestations (Pathophysiology and Genetics of Migraine. Headache. p. 88–99; Goadsby et al., Physiol Rev 97(2):553–622, 2017). Migraineurs exhibit photic allodynia and dysfunctional baseline central sensory processing indicating the brain of a migraineur differs from a nonmigraineur even at baseline (Kim et al., Cephalalgia 30(1):53–61, 2010; Vanagaite et al., Cephalalgia 17(7):733–741, 1997). Genetics are known to play a part in migraine as there is a statistically higher incidence of migraine amongst first degree relatives and in identical twins with migraine (Goadsby and Holland, Neurol Clin 37(4):651–671, 2019). Studies examining the potential mode of inheritance have been conflicting, indicating the etiology of migraine likely stems from a complex interaction between genes and the environment (Pathophysiology and Genetics of Migraine. Headache. p. 88–99). There is a consistent correlation of migraine with aura with disorders such as familial hemiplegic migraine illustrating the importance of genetics (Pathophysiology and Genetics of Migraine. Headache. p. 88–99). In addition, environmental triggers such as changes in weather and different food are known to play a significant role in migraine generation. This chapter will review the current knowledge of the pathophysiology of migraine through an examination of the four major phases of a migraine: premonitory, aura, headache, and postdrome.