I have been variously diagnosed by many Drs. and Neurosurgeons over 30 years as having "Atypical Migraine like stress headaches" as I do not have auras, flushing or light flashes before onset. Barometric changes seem to trigger my "migraines" more than anything else. Fiorinal w/ Codeine has been the only drug I have been prescribed that has proven effective. I do have rebound headaches two to three days after using more than one capsul.