system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do hangovers amplify sounds and lights to an almost painful level?
gpt
alcohol essentially dehydrates your body, 'stealing' water from your cells etc. among other things, but this is the most important one for neurological problems:
the brain is mostly water (aquaeos substances and so on) and due to osmotic tendencies of water, water from the brain will be relocated to other cells that need it. this result in undersupply of the brain, which leads to several problems such as headaches, sensitivity to sounds and brith light.
furthermore, most people drink alcohol in the evening and go to bed drunk. during the night, you body still uses some water, but it can't be replaced, because you're asleep and can't drink. this further amplifies the effects of dehydration.
this problem can be circumvented by drinking water alongside alcohol. for any measure of alcohol drink a glass of water. you'll drink less i.e. spend less money, get less drunk and have a smaller (if any) hangover.