I thought the main cause of a hangover was dehydration and the cure was drinking more water?
edit: according to this page[1] there's a combination of things:
- an inflammatory response
- irritated stomach lining
- blood sugar crash
- blood vessels expand
- alcohol can prevent deeper stages of sleep so you aren't rested the next day
[1] https://www.mayoclinic.org/diseases-conditions/hangovers/sym...
"Cured" by additional alcohol consumption. This "cure" can lead to multiday "chain" drinking.
Toxic chemical flowing through your body, makes sense to me.