How does alcohol affect the liver?
Any time we drink alcohol, the liver must break it down prior to removal from the body. However, due to the toxicity of the products of alcohol's metabolism, some liver cells die during this process. Having a break from alcohol is important to allow the liver to recover and make new cells. Sustained heavy drinking doesn’t allow the liver time to do this.
This is thought to be why the liver is the organ that sustains the greatest degree of tissue damage through heavy drinking, which leads to alcohol-related liver disease.8
Find out if your drinking could be causing you harm
The stages of alcohol-related liver disease
Alcohol-related liver disease is a spectrum of disease that broadly consists of three stages, each increasing in severity. It also increases the risk of developing liver cancer.
1. Alcoholic fatty liver disease
‘Fatty liver’ develops because of a build-up of fat in the cells in the liver.9 And drinking a large amount of alcohol, even for just a few days, can lead to a build-up of fat in the liver.10
It is estimated that alcohol-related fatty liver disease develops in 90% of people who drink more than 40g of alcohol (or four units) per day.11 That’s the equivalent of two medium (175ml) glasses of 12.5% ABV wine, or less than two pints of regular strength (4% ABV) beer.
This stage of alcohol-related liver disease does not usually cause any symptoms and may only be identified through a blood test. It’s also reversible by reducing your long-term alcohol consumption below the UK Chief Medical Officers’ (CMOs) low risk drinking guidelines. long term.
Your liver will start shedding excess fat if you stop drinking for at least two weeks12 and - after that - ensure you do not exceed the CMOs’ low risk drinking guidelines. But if you don’t reduce your drinking at this stage, in up to a third of people with this condition, it will progress to the much more serious stages outlined below.
Find out more about the UK low risk drinking guidelines
2. Alcohol-related hepatitis
Alcohol-related hepatitis is a potentially serious condition caused by heavy alcohol consumption over a longer period. Between 10–35% of individuals with alcohol-related fatty liver disease who continue drinking heavily will develop alcohol-related hepatitis.13
While alcohol-related hepatitis usually occurs after years of harmful drinking, it can also occur if you drink a large amount of alcohol in a shorter period of time.14
As with fatty liver disease, alcohol-related hepatitis may be reversed if you stop drinking. However, continuing to drink any amount of alcohol when you have alcohol-related hepatitis will increase the risk of developing cirrhosis.
Cirrhosis of the liver has several causes, one of which is alcohol. The third stage of alcohol-related liver disease is cirrhosis – where healthy liver tissue has been replaced permanently by scar tissue. This is the result of long-term, continuous damage to the liver.
Up to one in every five long-term heavy drinkers will develop alcohol-related liver cirrhosis.15 While cirrhosis is not reversible, there is good evidence that stopping drinking completely improves the outcome for some people.16
If you have cirrhosis and do not stop drinking, then you are likely to die from liver failure. 5,840 people in the UK died of alcohol-related liver disease in 2019.17 There is always a shortage of donor organs and people who are not abstinent cannot usually access liver transplants in the UK.
Alcohol-related cirrhosis increases the risk of developing liver cancer.18,19 Of people with liver cirrhosis, every year almost three out of every 100 (2.9%) of them will develop alcohol-related liver cancer.20
Find out more about liver cancer and alcohol.