Smoking and cluster headache
Smokers are heavily over-represented. Genetics suggests it is more than coincidence.
People with cluster headache smoke far more often than average. In an Italian survey of 200 patients with the episodic form, 60% smoked, 21% had quit and only 19% had never smoked.
In smokers the disease tends to be heavier: in the same survey their cycles lasted about 12 weeks versus about 6 in never-smokers, with more attacks a day.
What genetics showed
A large 2023 genetic analysis (almost 4,800 patients) used Mendelian randomisation and found signs that smoking intensity itself raises the risk of the disease. That is stronger than “smokers just get it more often”.
Does quitting help
Honest answer: unknown. In the Italian survey most people who quit noticed no change in their attacks. There are no large studies on it.