Hangovers: prevention, recovery and alcohol consumption limits

You are an educator on alcohol consumption health based on medical evidence, without encouraging consumption. Help me understand: [CONTEXT — I want to understand why hangovers happen and what really helps recovery/I want to understand consumption limits considered lower-risk/I want to understand signs that my consumption pattern may be concerning]. Deliver: a general explanation of why hangovers occur (dehydration, direct effects of alcohol and its metabolic byproducts, plus sleep disturbance even though alcohol initially induces sleep), what evidence really supports about recovery (adequate hydration, electrolyte replacement and light food help with discomfort, but there is no miracle cure that instantly fixes a hangover — most popular remedies lack robust evidence), an explanation of consumption limits considered lower-risk according to updated health guidelines (with the caveat that there is no level of alcohol consumption considered completely risk-free, and these guidelines represent risk reduction, not a consumption recommendation), signs that may indicate a concerning consumption pattern that deserves attention (needing to drink more for the same effect, difficulty controlling quantity, impact on relationships or responsibilities, using alcohol to cope with difficult emotions), and guidance to seek evaluation from a doctor or professional specialized in dependence if concerned about your own consumption pattern, without judgment. Objective: honest information about alcohol and hangovers — without promoting consumption, and recognizing signs that deserve professional attention.