Whether you’re getting drunk, smashed, plastered or wasted, you're going to exhibit the number of visible and rather embarrassing effects of getting inebriated. This can range from belting your favorite song to vomiting on your flatmate’s shoes. But what exactly is happening to your body when you’re getting drunk?

IFLScience teams up with Stephen Braun, author of Buzz: The Science and Lore of Alcohol and Caffeine, to uncover what’s happening to our bodies when we’re getting drunk.

Let’s start from the beginning of the night.

At first you feel great

It’s a Friday night, you have a glass of wine or beer in your hand and it’s been a really long week. The first thing to know while the drinks start flowing is that alcohol is a drug. The effects of this drug are highly dependent on how much you drink and how quickly. While some drugs are more precise in their effect on the body, alcohol is the complete opposite.

“Alcohol is like the hand grenade or a bomb. It blows up and goes everywhere,” Braun tells IFLScience.

As you drink, alcohol – or ethanol – travels to your stomach and very quickly gets absorbed into your bloodstream. It’s then transmitted throughout the body.

“Your body responds to alcohol as if you’ve taken a very nasty poison and its geared to get rid of it,” Braun explains.

The liver begins the process of breaking the alcohol down. It produces an enzyme called alcohol dehydrogenase, which converts alcohol into acetaldehyde. Acetaldehyde, which is thought to play an important role in a hangover, is then broken down into acetic acid. If you drink more alcohol than your liver can process, you start to get drunk. How quickly you get drunk is dependent on a number of factors, such as how much you’ve eaten beforehand. 

While alcohol is known to be a depressant, it actually has two different "phases."

“In the first half an hour or so of drinking, you’re going to experience stimulating effects and euphoria. Alcohol reduces your inhibitions and will release a little dopamine – the brain’s big reward molecule – so you’re going to feel good,” Braun says.

Then the depressive effects kick in

You’ve had a few more glasses and you’re becoming clumsier, you’re not reacting to situations as quickly and your vision can start to get more blurry. This is when the alcohol starts effecting other parts of the brain – exerting the depressive effects.

Alcohol is known to increase the effects of the inhibitory transmitter Gamma-Aminobutyric Acid (GABA) in the brain. GABA is a neurotransmitter that dampens responses. This causes the sluggish movements and impaired speech that alcohol is known for.

“This isn’t the time to make important decisions,” Braun says. This is because alcohol depresses the behavioral inhibitory centers in the cerebral cortex, making you more likely to do things, or someone, that you wouldn’t if you were sober.

You need to pee – a lot

You’ve just come back from the toilet and find yourself needing to go back again. That’s because your liver is working furiously to get the alcohol out of your body. Alcohol blocks an antidiuretic hormone, also known as vasopressin, in your body. Vasopressin normally keeps the kidneys from excreting too much fluid by telling the kidney to reabsorb water. As vasopressin is blocked, your body starts excreting more liquid from your body than you’re actually taking in from the beer or wine.

“You end up dehydrated and that’s a big reason for hangovers,” Braun explains.

You might want to have sex, but...

While alcohol may stimulate your sex drive, it can dampen sexual responses. As Shakespeare so eloquently put it, alcohol “provokes the desire, but ... takes away the performance.”

“After that third or fourth glass of wine, pretty much everything is going to go downhill. From a purely physiological standpoint, alcohol is just bad for sex,” Braun says.

Alcohol makes it harder to get an erection, lubrication doesn’t work as well and orgasms are harder to achieve.

You may wake up the next day, look at your bed partner and wonder: What was I thinking?

“Obviously you weren’t thinking,” Braun says while chuckling. “Under the influence of alcohol, you may find yourself becoming much more attracted to someone then you would if you were sober. That has to do with putting a break on your frontal lobe and loosening up all the emotional centers of the brain.”

A study, published in the journal Addiction, suggests that the phenomena more commonly referred to as beer goggles is down to our ability to assess facial symmetry. Alcohol reduces our ability to evaluate facial symmetry, which some suggest contributes to attractiveness and human mate selection.