This source talks about migraines and the symptoms that are given during an attack. It explains how everyone experiences them differently, but the amount of pain can be common. For example, symptoms may include: stiff neck, concentration problems, nausea, sensitivity to light or smells, and many others.
Doctors are thinking that the trigeminal nerve has to do with the facial pain and generates from almost nothing. The trigeminal nerve is the fifth cranial nerve which is slightly near the ear and branches off towards the eyes and lower jaw. This nerve could be causing the excruciating pain for some patients during a migraine attack.
Another belief is the pons (part of the brainstem that links the medulla oblongata and thalamus) could be triggering the pain. During a study in Honolulu, Dr. Goadsby took patients in the middle of a migraine attack and put them under a resolution camera which showed the pons lighting up. She assumes that this has lead to the patients experiencing pain all over the body.
I find this information very useful because I often get migraines myself. It is common in my family and I think finding a solution to stop them from occurring in the future is important.
I think in the Neurology field many doctors receive patients coming in with migraines and this is helpful for patients that get them often.