How Does Alcohol Make You Drunk?

It’s fairly easy to recognize when someone is drunk. Their speech becomes slurred, their movements uncoordinated, and their judgment and inhibitions go out the window. But have you ever wondered, why does alcohol make you drunk? What exactly is happening inside the body and brain?

In this post, we’ll explore how alcohol interacts with our bodily systems to cause many of the symptoms we associate with being drunk. We’ll also offer tips on how to avoid intoxication. Let’s get started!

What Exactly Is Alcohol?

What is in alcohol that makes you drunk? To understand the answer, it’s helpful to understand exactly what alcohol is. When we talk about alcohol in the context of beverages, we’re referring to active ingredient ethanol. This clear, colorless liquid is produced through the process of fermentation, in which yeast converts sugars into alcohol. For instance, beer is made from the sugars in malted barley, wine from the sugars in grapes, and vodka from the sugars in potatoes.

When we drink beverages that contain ethanol (the active compound in alcohol), the chemical enters our bloodstream quickly, circulates throughout our body, and travels to various organs. We can gauge how much alcohol has affected us from our blood alcohol content (BAC), which tells us just how much alcohol has entered our bloodstream. For instance, a BAC of 0.08 indicates that there are 0.08 grams of alcohol per 100 milliliters of a person's blood, which is often the legal driving limit.

Alcohol’s effects are more obvious at greater blood alcohol concentrations. At lower BAC levels, people might experience feelings of relaxation and sociability. However, when BAC rises, these sensations can morph into unsteady movements and poor judgment — and at dangerously high concentrations, we can experience loss of consciousness or alcohol poisoning.

How Does Alcohol Get You Drunk?

Many of the signs we associate with being drunk — such as slurred speech, poor coordination, and impaired judgment — are due to alcohol’s effect on the brain. In fact, alcohol typically reaches our brain within 5 minutes, and we can begin feeling its effects within 10 minutes. But what makes you drunk exactly?

Alcohol crosses something called the blood-brain barrier, a group of cells surrounding the brain that protects it from invaders such as toxins and bacteria. Some substances are able to pass through if they dissolve easily in water or fat, and alcohol is one of those substances.

Once alcohol enters our brain, it triggers a number of processes that lead to the typical signs of drunkenness. Our brains are highly complex structures that contain a delicate balance of neurotransmitters — chemicals that carry signals between nerve cells. Two neurotransmitters in particular are responsible for causing many of the symptoms we associate with intoxication.

• Gamma-aminobutyric acid (GABA). GABA is a neurotransmitter that slows brain activity. When alcohol enters our brain, it attaches itself to GABA receptors, which are like little docking stations. By binding to these receptors, alcohol slows our brain function. This is why we feel more relaxed and calm as soon as we start drinking.
• Glutamate. Glutamate, an excitatory neurotransmitter, “excites” (stimulates) nerve cells to deliver messages in our brain. It’s vital for proper brain functioning. Alcohol inhibits glutamate, decreasing the speed of neural activity and slowing brain processes. This is partly why our reasoning and judgment become impaired the more alcohol we consume.

The more alcohol we consume, the more alcohol builds in our bloodstream, and the greater the effects on GABA and glutamate. This is why intoxication leads to slower reaction times, slower thought processes, loss of motor control, slurred speech, dizziness, and lowered inhibitions.

What Parts of the Body Process Alcohol?

Now that we have a general understanding of how alcohol causes intoxication, let’s get a bit more specific: what parts of the brain does alcohol affect that makes us drunk? Here’s a look at 6 areas of our brain that alcohol acts on to cause those familiar symptoms of intoxication:

• The frontal lobe. Located right behind our forehead, the frontal lobes serve as our brain’s command center. They’re responsible for all sorts of higher mental functions, such as planning, organizing, problem-solving and decision making. They also regulate our emotions and control our impulses. This is why, after a few drinks, we might make poor decisions, become irrational, or get upset more easily.
• The amygdala. The amygdala processes emotions, especially those related to fear, aggression, and social interactions. Alcohol can decrease the amygdala’s inhibitory mechanisms, leading to increased aggressive behaviors and reduced fear. This is why we might engage in riskier behaviors when we’re drunk.
• The hippocampus. This part of our brain forms, organizes, and stores new memories. It also helps connect emotions and senses (such as smell and sound) to certain memories. Consuming alcohol disrupts the process of forming memories, leading to “blackouts” or difficulty remembering events that occurred while we’re intoxicated.
• The thalamus. The thalamus is a relay station for most of the sensory information coming into the brain (excluding smell). It directs incoming sensory data to appropriate areas of the cortex for further processing and plays a role in consciousness and alertness. Alcohol can interfere with the thalamus’ ability to transmit this information efficiently, leading to distorted perceptions or reduced sensations.
• The cerebellum. This small part of the brain plays a big role in ensuring our movements are coordinated and precise. From simple activities like picking up a pen to complex activities like rock climbing, the cerebellum ensures we move with ease and accuracy. As alcohol affects this region, the precision and coordination we often take for granted can become compromised. This is why we might have trouble doing something as simple as walking in a straight line.
• The medulla. Located near the place where our brain meets our spinal cord, the medulla oversees several involuntary functions, such as breathing, heart rate, and blood pressure. Alcohol slows the functions controlled by the medulla, leading to drowsiness or even unconsciousness. This is why after heavy drinking, we might experience slowed breathing or a drop in body temperature.

How Does Being Drunk Feel?

With alcohol affecting all these different parts of our brain, it’s no wonder we start to lose control of our movements, speech, and judgment!

Feeling drunk might initially involve a short-lived “buzz” caused by a rush of dopamine. We might then feel sluggish and uncoordinated as the depressant effects kick in.

The neurotransmitter chaos created by alcohol can lead to unpredictable moods — laughing one minute and crying the next. We could even get aggressive or make impulsive decisions.

If we continue to drink, our coordination is likely to worsen, we might slur our words, or we could be hit by a wave of fatigue (and maybe even fall asleep!).

Why Alcohol Affects People Differently

How much alcohol makes you drunk? If you ask two different people, you’ll get two different answers. That’s because a lot of factors go into how alcohol affects us.

1. Weight. We experience the effects of alcohol more strongly and more quickly the less body tissue we have to absorb it. A larger body provides more room for the alcohol to spread.
2. Sex assigned at birth. Males and females have differing rates of alcohol metabolism because of differences in body composition. Is it true that males can eliminate alcohol from their bodies faster? Turns out this is, indeed, the case. Women generally have a greater percentage of body fat, which keeps alcohol in their system longer. They also have fewer alcohol-metabolizing enzymes and less bodily water to dilute alcohol.
3. Age. As we get older, our metabolism slows, our body fat percentage rises, and our water content falls. As a result, we feel the effects of alcohol more quickly, and the alcohol stays in our system for longer.
4. Genetics/ethnicity. Some genetic mutations are particularly common in East Asian and Native American ethnic backgrounds that result in slower rates of alcohol metabolism. These mutations reduce the activity of an enzyme important in breaking down alcohol’s toxic compounds. As a result, people with this ethnic background might experience greater feelings of intoxication.
5. The type of alcohol. Alcohol content varies between drinks. Spirits that are highly concentrated, like vodka and gin, are absorbed by our body more quickly. The body also absorbs champagne and other bubbly drinks like soda mixes more quickly than other beverages.
6. How quickly we drink. Drinking a lot of alcohol in a short amount of time is going to make us feel intoxicated very quickly, regardless of what we drink. Chugging is dangerous because we may not realize how drunk we’re becoming until well after our last drink.
7. How much we’ve eaten recently. Food in our stomach slows our system’s rate of alcohol absorption. Alcohol is absorbed more rapidly by an empty stomach, which leads us to feel its effects faster and harder.
8. Medications. Alcohol absorption may be affected by certain drugs, or they may combine with alcohol and heighten its effects. For instance, opioids, cannabis, and over-the-counter cold and pain medications can increase the effects of alcohol. However, stimulants such as caffeine can mask intoxication.
9. Our overall health. Our body's ability to break down and eliminate alcohol can be impacted by a number of medical conditions, including those that influence liver and kidney function.

Tips for Avoiding Intoxication

So what can we do to avoid intoxication? Is it possible to still drink without becoming drunk? Yes! However, given alcohol’s negative effects on both our short- and long-term physical and mental health, it’s worth limiting consumption or quitting alcohol altogether. It’s even possible our body is sending us signals to reduce drinking. However, if we do choose to drink, here are 6 tips for avoiding intoxication:

• Practice mindful drinking. Mindful drinking involves being more conscious and present while we drink. It improves our self-awareness and self-control, and encourages us to make more intentional choices. For instance, we can practice mindful drinking by setting limits before we go out or by paying attention to the flavors of the beverage we’re consuming and the atmosphere of our environment.
• Count your drinks. It’s easy to lose track of the amount of alcohol you consume. Try using a notepad app to document every drink you have in one sitting — whether at a party, dinner, or event. This can help you become more aware of how much you’re consuming. You can even take this one step further by limiting yourself to one drink every hour.
• Sip slowly. Savor each drink, taking slow sips and staying involved with other activities, such as playing trivia or chatting with friends. It can help to stick to drinks that take time to finish, such as beer or wine (as opposed to shots or mixed drinks, which are intended to be gulped down).
• Don’t mix drinks. Mixing different types of alcohol can rapidly bring up BAC levels and make us intoxicated much more quickly than if we stick to one kind only. Mixing drinks may also cause us to consume a larger amount of alcohol in a short period of time.
• Hydrate, hydrate, hydrate. For every alcoholic drink you have, try consuming a full glass of water. This helps us stay hydrated, and it limits the amount of alcohol we consume. It also gives our liver time to break down the alcohol. Even moderate levels of alcohol cause dehydration, and drinking water can slow this effect down.
• Eat something. It’s best not to drink on an empty stomach, so make sure to eat beforehand, or have a snack while you’re drinking. As we’ve discussed, food slows the processing of alcohol. Eating can also help us drink at a slower rate, since we’re doing something in addition to drinking.

The Bottom Line

Many of the signs we associate with intoxication arise because alcohol slows brain processes and activity. It acts on important neurotransmitters and affects the parts of our brain associated with balance, coordination, judgment, memory and decision-making. While no one is immune to alcohol’s intoxicating effect, various factors can influence its intensity, such as our weight, sex, age, and drinking speed. We can avoid intoxication by practicing mindful drinking, hydrating as we drink, and eating food while drinking.

If you’re looking to cut back on your alcohol consumption but not sure where to start, Reframe can help. We’ve helped millions of people not only change their relationship with alcohol, but develop healthier lifestyle habits that enhance their well-being.