Alcohol is an effective short-term anxiolytic. It genuinely works, which is the problem — for socially anxious people in particular it’s often the thing that makes an evening possible, and it’s one of the most reliable ways to end up drinking more than you meant to.
What happens the next day
Alcohol enhances GABA, the main inhibitory neurotransmitter, and suppresses glutamate, the main excitatory one. Your brain compensates: it downregulates GABA sensitivity and upregulates glutamate.
When the alcohol clears, those adaptations remain for a while, and you’re left in a net excitatory state. Hence the racing heart, the jitteriness, the sense of dread with no content, the hypersensitivity to noise. Commonly called hangxiety, and it isn’t psychological — it’s rebound.
It’s typically worst in the second half of the night and the following morning, and it’s worse the more you drank and the later you drank it.
The sleep half
Possibly more important than the direct effect. Alcohol shortens sleep latency — you fall asleep faster — and then wrecks the architecture: REM is suppressed early and rebounds later, and the second half of the night becomes fragmented and shallow.
So you sleep badly, wake at four, and start the day with reduced sleep and rebound arousal. Sleep loss raises anxiety considerably on its own, and a good proportion of what people call hangxiety is that.
The loop
Anxiety, drink, relief, worse anxiety tomorrow, drink again. It builds quietly, and it’s one of the commoner routes into problem drinking — particularly for people with social anxiety, where the rates of alcohol misuse are markedly elevated.
There’s a second, subtler cost. Drinking before a social occasion is a safety behaviour, which means the evening teaches you nothing: you got through it, and the credit goes to the alcohol.
What to do about it
Test it rather than assume. Two or three weeks without, with a daily anxiety rating, tells you more than any general advice — and the effect size surprises people in both directions.
If you keep drinking, the practical levers are: earlier rather than later, water alongside, and — the significant one — not using it as the tool for getting through a specific feared situation.
Some exposures need to happen sober, or the treatment doesn’t work.
The safety note
If you drink heavily and daily, don’t stop abruptly. Alcohol withdrawal can be medically dangerous and occasionally fatal, and it needs medical supervision. Ask a doctor rather than a website, and say honestly how much you drink.