10 Things That Happen to Your Body When You Drink Alcohol (The Real Deal)

Drinking alcohol isn’t just about the buzz — it’s a whole-body experience, and some of it isn’t exactly glamorous. From your brain to your liver, your body works hard to handle the booze, often with surprising side effects. Let’s break down what really happens when you take that first sip, and every sip after.

1. Slows down your brain

Alcohol acts as a depressant on your central nervous system. It interferes with the neurotransmitters (the chemical messengers) that help brain cells communicate. Specifically, it boosts GABA, a neurotransmitter that slows brain activity, and inhibits glutamate, which usually excites brain cells. The result? Slower thinking, reduced reaction times, and impaired coordination. That’s why after a few drinks your speech slurs and your balance goes out the window.

2. Impairs your judgment

The prefrontal cortex — the part of your brain responsible for decision-making and impulse control — is especially sensitive to alcohol. When you drink, this area gets “dampened,” which means you’re less able to weigh consequences or resist risky behavior. That’s why your “brilliant” late-night texts or dance moves might not age well.

3. Dehydrates you

Alcohol is a diuretic, meaning it increases urine production by inhibiting the release of vasopressin, a hormone that tells your kidneys to hold onto water. More trips to the bathroom means you’re losing fluids faster than you’re replacing them, which leads to dehydration. This contributes to classic hangover symptoms like headache, dry mouth, and fatigue.

4. Upsets your stomach

Alcohol irritates the stomach lining and increases acid production. This can cause inflammation (gastritis), nausea, and even vomiting in larger amounts. Plus, alcohol slows digestion, which means food and alcohol stay in your stomach longer — not a great combo if you’re already feeling queasy.

5. Slows down your liver

Your liver is the heavy lifter when it comes to processing alcohol. It breaks alcohol down into acetaldehyde, a toxic substance, and then into harmless acetate. But this process takes time — your liver can only metabolize about one standard drink per hour. Drinking faster than your liver can keep up means alcohol builds up in your blood, causing intoxication. Over time, heavy drinking can lead to fatty liver disease, inflammation, fibrosis, or even cirrhosis.

6. Lowers your immune defense

Alcohol messes with the immune system in several ways. It impairs the function of white blood cells, which fight off infections, and disrupts the production of cytokines, molecules that coordinate immune responses. This leaves you more vulnerable to infections, including respiratory illnesses like pneumonia or even COVID-19.

7. Messes with your sleep

While alcohol can make you fall asleep faster by depressing the nervous system, it disrupts your sleep cycle, especially REM sleep, which is critical for memory, learning, and mood regulation. It also causes more frequent awakenings during the night, resulting in poorer quality sleep and morning grogginess.

8. Makes you gain weight

Alcohol is calorie-dense — about 7 calories per gram (almost as much as fat). Plus, it’s often consumed alongside salty or fried snacks, which pile on the calories. Alcohol also interferes with how your body burns fat by prioritizing metabolizing alcohol over nutrients, slowing your metabolism and encouraging fat storage.

9. Dilates your blood vessels

Alcohol causes vasodilation — the widening of blood vessels — which makes you feel warm and flushed. This also causes blood pressure to drop temporarily, which can sometimes lead to dizziness or fainting, especially when standing up quickly.

10. Affects your mood

Though alcohol initially boosts dopamine (the feel-good neurotransmitter), it’s actually a depressant. After the buzz wears off, levels of serotonin and other mood-regulating chemicals drop, which can lead to feelings of anxiety, sadness, or irritability. This is why alcohol can worsen depression or anxiety, especially with frequent or heavy drinking.

Understanding these effects doesn’t mean you need to swear off alcohol — just that knowing what it’s doing inside your body can help you make smarter choices and maybe avoid some nasty side effects.