The causes of Migraines are very difficult to tell. We don’t fully understand them. Part of that is because enough research doesn’t go into migraine and headaches in general – I can’t just say migraines. We used to believe it was all vascular, meaning too much blood was rushing up to the head. We now realize it’s only a tiny portion of it and it’s mainly a chemical or neurotransmitter. A chemical P (or substance P) is released into the head and that basically turns on the nerves and causes more pain. There’s a small portion of blood flow issues, but we don’t fully understand all the causes related to it. We also don’t fully understand everything that turns off in a migraine.