What effect does alcohol have on your body?

Glasses of white and red wine in a row
Written by Olivia Hunt
1st Aug 2022 • 9 minute read
Dr Nadja Auerbach
Reviewed by
Dr Nadja Auerbach, MBBS BSc Dip IBLM/BSLM

Drinking alcohol affects almost every part of your body — particularly your brain, liver, heart, and skin. The more you drink, the greater the effect it has on your body. Drinking the occasional glass of wine with dinner isn’t a cause for concern. But if you drink a lot over a long time, it can significantly affect your health and lead to long-term conditions.

Short-term effects of alcohol on your body

Everyone responds to alcohol differently, and what will cause a hangover for one person might not have the same effect on someone else. Genetics can play a role in this as some people don’t have the proper enzymes to break down alcohol — alcohol intolerance. This is most common in people of Asian descent.

As a general rule of thumb,  if you drink more than 6 units in one go, you’re likely to develop a hangover. This equates to about 3-4 pints of beer or 4 standard glasses of wine.

If you drink a lot of alcohol, it’s worth checking your liver health. You can do this through your GP or with an at-home liver blood test (formerly known as a liver function blood test). It’s important to note that this test can’t formally rule out or diagnose liver disease without more medical context or further investigation by your GP.

You should only do a liver blood test if you believe you might be at risk of alcoholic liver disease.

Why do you get hangovers?

It takes your liver about an hour to remove 1 unit of alcohol from your body — about half a glass of wine. Depending on how much alcohol you have, it might lead to a hangover. 

​​Ethanol (alcohol) is toxic and acts as a diuretic — a substance that makes you urinate more frequently. Excess urination can increase the risk of dehydration and loss of vital electrolytes.

Dehydration is responsible for some of the symptoms you feel when hungover — like dizziness, lightheadedness, and thirst.  

Alcohol is broken down by your body into an even more toxic substance called acetaldehyde, which your body will eventually get rid of. Some studies have shown that this toxic substance causes symptoms like nausea and vomiting.

You can reduce your chances of getting a hangover by:

  • drinking water before going to bed 
  • eating a substantial meal before drinking — you might feel the effect of alcohol more quickly when drinking on an empty stomach
  • drinking in moderation, or avoiding alcohol altogether

Long-term effects of alcohol on your body

Drinking excessive amounts of alcohol for many years affects many of your organs — sometimes causing permanent damage to your brain, nervous system, heart, liver, and pancreas.

Heavy drinking can also increase your blood pressure and blood cholesterol levels, increasing your risk of heart attacks and strokes.

Drinking too much can also lead to alcohol-related liver disease (ARLD) — typically in 3 stages. 

Stage one: alcoholic fatty liver disease

Fatty liver disease happens when you drink a lot of alcohol over 2 or 3 weeks. A build-up of fat starts to form in your liver.

Risk factors for alcoholic fatty liver disease include:

  • men who drink more than 8 units a day
  • women who drink 5 units a day

Fatty liver disease isn't severe and typically doesn’t have any symptoms. Stopping drinking for around 2 weeks gives your liver enough time to process the fats and reverse the condition.

Stage two: alcoholic hepatitis (liver inflammation)

Alcoholic hepatitis happens over a long time (and isn't related to infectious hepatitis, usually caused by a virus). Alcoholic hepatitis has the potential to be more serious than fatty liver disease. But alcoholic hepatitis is usually reversible if you stop drinking alcohol permanently.

Stage three: cirrhosis (scarring)

Drinking too much alcohol puts strain on your liver, which can result in inflammation. This can lead to irreversible scarring — called cirrhosis. The scar tissue permanently damages the liver, making it harder to function normally and remove toxins (like alcohol) from your body. This can lead to permanent damage.

Are there any symptoms of alcoholic-related liver disease?

Alcohol-related liver disease doesn’t tend to show any symptoms until your liver is severely damaged. 

If you drink a lot of alcohol, it's worth regularly checking your liver function. You can do this through your GP or with an at-home liver blood test.

What is binge drinking?

Binge drinking refers to drinking lots of alcohol in a short space of time — usually to get drunk.  It’s classed as more than 8 units for men and 6 units for women in a single session. 

This is equivalent to:

  • 2 glasses of wine and 2 small bottles of 5% beer (8 units)
  • 1 pint of beer, 1 medium glass of wine (175ml), and 1 glass of champagne (6 units)

Drinking large amounts of alcohol can make you more vulnerable to accidents and harm — your body can only process 1 unit of alcohol an hour.

Glasses of white and red wine in a row

How does alcohol affect your behaviour?

While drinking alcohol can make you feel more confident and talkative, there are many risks associated with drinking a lot of alcohol. 

Some of these include:

  • accidents and injury 
  • violent and antisocial behaviour 
  • unprotected sex — this can result in unplanned pregnancies and sexually transmitted infections (STIs) 
  • losing personal items — like your wallet, keys, and phone
  • time off from work or college — which can put your job or education at risk

How does alcohol affect your heart?

After drinking 1-2 units of alcohol, your heart rate temporarily speeds up, and your blood vessels expand. At this stage, you might feel more confident and chatty. 

Over time, binge drinking can cause damage to your heart by:

  • increasing your blood pressure — puts a strain on your heart and can increase your risk of heart disease or a heart attack
  • increasing your cholesterol and triglyceride levels
  • weakening your heart muscle (cardiomyopathy)

In susceptible people, minimal amounts of alcohol can raise triglyceride levels. Having no more than 14 units a week (about 6 pints or 7 medium-sized glasses of wine) can help keep triglyceride levels low, as well as having a few alcohol-free days and not binge drinking.

How does alcohol affect your brain?

One of the most noticeable effects of alcohol on your body is its effect on your brain. After just a few drinks, you’ll start slurring your speech. This happens because alcohol slows down the communication between your brain and your body.

Chronic alcohol consumption also causes cognitive deficiencies — like memory problems, issues with problem-solving, processing speed, and the ability to read with speed.

Because of this, drinking also affects your balance, decision making, and emotions. After a few drinks, you might notice that you start speaking faster, become more relaxed, and more confident. That’s because part of the brain we associate with inhibition is ‘depressed’ by alcohol.

Alcohol affects your mental health through its effect on thiamine (vitamin B1) —  a nutrient essential for brain function. Alcohol can lower the absorption of thiamine and affect how it’s used in your cells.  Thiamine deficiency is linked to common mental health disorders. This could be why drinking alcohol is associated with negative emotions — like anger, anxiety, and depression.

Over time, alcohol dependence can cause your brain to shrink — this gets worse the older you are and the more you drink.

Alcohol has a huge social impact on a lot of people and socialising and forming close relationships is important for psychological wellbeing. Above this, alcohol might affect your mood, anxiety, memory, and so on.

What effect does alcohol have on your lungs?

Heavy drinking can weaken your immune system over time. It’s linked to lower amounts of white blood cells called ​​lymphocytes (also known as T cells), which help protect you from bacterial and viral infections. 

Alcohol also affects your central nervous system (CNS) cell function — particularly astrocytes and microglia cells. 

Astrocytes are cells that help send and receive signals from your brain and maintain your body temperature (homeostasis). Microglia cells also play a huge role in supporting your immune response against infections affecting your CNS.

If you have alcohol use disorder (AUD), you’re more likely to develop:

  • pneumonia
  • tuberculosis (TB) 
  • respiratory syncytial virus (RSV) infection
  • acute respiratory distress syndrome (ARDS)

What effect does alcohol have on your digestive system?

Alcohol consumption can affect your digestive system. Alcohol slows down gut motility and at worst, can damage your intestines. This makes it harder to digest food and nutrients. This can lead to malnutrition — when your body doesn’t have the nutrients it needs.

More immediate effects include:

  • gassiness
  • bloating
  • a feeling of fullness in your abdomen
  • constipation — due to dehydration
  • diarrhoea

What effect does alcohol have on your skin?

Over time, excessive drinking can lead to skin problems.

Some of these are:

  • jaundice — when the skin and the whites of your eyes turn yellow due to a high level of a yellow pigment called bilirubin, as a result of liver damage
  • pruritus — dry and itchy skin
  • hyperpigmentation — patches of skin that turn darker in colour than the normal surrounding skin
  • urticaria (hives)

How many units can you drink?

Alcohol units were first introduced in the UK in 1987 to help the public keep track of their alcohol consumption.

Units explain the amount of pure alcohol in your drink. The size of your drink and the strength of the alcohol can affect the number of units, so it’s important to check this if you’re keeping track each week.

Currently, men and women shouldn’t consume more than 14 units in a week. You should aim to spread your drinking over 3 days or more. And you can cut down your alcohol consumption by having a few drink-free days in the week.

How to reduce alcohol consumption safely

If you want to cut down on the amount of alcohol you drink, you should get medical advice first. This is because you can get physical withdrawal symptoms, like shaking, sweating or feeling anxious until you have your first drink of the day. It can be dangerous to stop drinking too quickly without proper help.

It’s also a good idea to develop a plan to help you get there one step at a time. 

Some helpful tips include:

  • setting a budget for how much you want to spend on alcohol every week or month
  • letting your friends and family know you’re cutting down — they can help support you
  • reducing the size of your drink — opting for a small glass of wine or half a pint
  • choosing lower strength alcoholic drinks
  • drinking a glass of water in between alcoholic drinks 

If you’re concerned about the amount of alcohol you drink and the effect it’s having on your physical and mental health, it’s a good idea to talk to your GP for advice. 

If you're worried about your alcohol consumption, you can also contact Drinkline, the national alcohol support service on 0300 123 1110.