There are several Hangover Scales, none of which is comprehensive. Factor analyses show several factors or clusters of symptoms, which does not clarify the situation since these factors intercorrelate, they are not independent. Is there any study that looks at dozens of symptoms and only considers orthogonal factors? I suspect that there will be one general factor with little else to show once this common factor is accounted for. We can then better understand the one underlying multi-faceted cause. Drinkers can identify their hangovers better than the scales.