BackgroundThe aim of this study was to examine the relationship between urine ethanol concentration and alcohol hangover severity.MethodsN = 36 healthy social drinkers participated in a naturalistic study, comprising a hangover day and a control day. N = 18 of them have regular hangovers (the hangover group), while the other N = 18 claim to be hangover immune (hangover-immune group). On each test day at 9.30 am, urine samples were collected. Participants rated their overall hangover severity on a scale from 0 (absent) to 10 (extreme), as well as 18 individual hangover symptoms.ResultsUrine ethanol concentration was significantly higher on the hangover day when compared to the control day (p = 0.006). On the hangover day, urine ethanol conce...