There are a number of reasons that your doctor might ask you to keep a migraine diary. If you have been suffering regular and severe attacks there could be a number of contributing factors, and being able to figure out what those factors are is step one to treating the migraines, and possibly even preventing them.
Migraine headaches are distinct from other types of headaches in that they typically occur regularly, sometimes on a yearly basis, others occur monthly or several times per month. They are described as throbbing, pounding and intense pain on one side of the head that may spread to the other side. Migraines are accompanied by nausea and/or vomiting and the person may experience sensitivity to light (photophobia),