There are a lot of hangover myths. No, they are not caused by dehydration, so drinking lots of water with your booze won't help. And no, they are not caused by blood sugar levels. Scientists do have one hypothesis about what causes them, however — and luckily we have a cure for it.
[Scientists] finally have a survey instrument that they can give somebody and assess, "You have a Level 9 hangover, and you have a Level 7 hangover," and they finally started to see that overlap with both migraine and also an inflammatory response, so the kind of thing you would have if you had the flu — where you feel achy and you feel slow and your brain doesn't work as fast and [you have] general malaise. Looking at that, they can go, "K, let's see if in fact this is an inflammation."
If you look at people with hangovers, the same markers in the blood that you would see with an inflammatory response, things like cytokines, for example — which are molecule[s] that the immune [system] uses to talk to itself — actually do seem elevated, and even better, you can induce what looks like a hangover by giving somebody those same molecules. ... That's good news because if you say, "Well, it's an inflammatory response," then maybe I can go with anti-inflammatory drugs, and we have those.
That's right. It's possible that the cure for a hangover may just be non-steroidal anti-inflammatory drugs like ibuprofin and asprin. So you've probably been doing it right all along.
Listen to the whole interview on NPR