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.
Though there is no proven mechanism for why smoking increases the frequency of migraines, it is possible that the smoking generates excessive amounts of free radicals, causing substantial oxidative stress, which is known to contribute to inflammation, which may then affect the nerves.
So, if you both smoke and suffer from migraines, the least you should try to do is keep your number of daily cigarettes down below 5.
Curt Hendrix M.S., C.C.N., C.N.S.