A study published in the Journal of Headache and Pain found that smoking 5 or more cigarettes a day can trigger migraines and that in general smokers have more migraines than non-smokers. The research involved 300 medical students who were well trained in being able to identify a migraine from another type of headache. According to Dr. Pascual, the lead researcher in the study, “smoking is a precipitating factor of this type of headache, as the prevalence of active smokers...