The Effect of Nasal Carbon Dioxide (CO2) in the Treatment of Mild Headache in People Who Experience Migraines

Inclusion Criteria: * Able to read and understand informed consent form and voluntarily consent to participate in this study by signing the IRB-approved informed consent form * Established diagnosis of migraine with or without aura per ICHD-II (patients with a diagnosis of only menstrual migraine are not eligible) * History of 2-8 migraine attacks per month during the 3 months prior to randomization * Have a typical migraine which progresses from a distinct mild headache to a moderate or severe migraine * Able to recognize a mild headache that could develop into a moderate or severe migraine Exclusion Criteria: * Have less than 48 hours of freedom from headache between attacks of migraine * Have 15 or more headache days per month * Are females who are pregnant or lactating * Use antipsychotic or antidepressant medications (unless only for migraine prophylaxis) within 12 weeks prior to randomization and for the duration of the study * Have a concurrent diagnosis of TMD or trigeminal neuralgia requiring treatment * Clinically significant deviated septum, nasal polyps or other nasal condition that prevents unrestricted breathing through each nostril * Have participated in another study with nasal CO2