Fig. 1

Relationships between the amount of alcohol consumption followed by a hangover and headache type according to alcohol flushing and gender. M migraine, T tension-type headache, and O “other headaches”. Current or past flushers and women were more susceptible to hangovers than never flushers and men, respectively, regardless of headache type. Among the never flushers, women with migraine were more susceptible to hangovers than women with “other headaches”. The statistical analysis was performed by the Cochran–Mantel–Haenszel test for trend adjusted for age. ^†p = 0.0005, ^††p < 0.0001 in comparison with never flushers; *p < 0.01, **p < 0.0001 in comparison with women