The liver breaks down over 90% of alcohol so it can be removed from the body. This process converts alcohol to acetaldehyde, a poisonous by-product that can damage liver cells and lead to inflammation, liver disease, and cancer. The more alcohol you drink, the higher your risk of damage to your liver.

How does alcohol damage the liver?

When alcohol is digested, over 90% is carried in the bloodstream to the liver so that it can be broken down (metabolised) by an enzyme called alcohol dehydrogenase (ADH) and removed from the body. 1, 2 ADH enzymes convert alcohol to acetaldehyde, a highly reactive and toxic chemical, and Group 1 carcinogen (the highest risk group, same as tobacco, asbestos and radiation).3, 4 

The liver can only break down around one standard drink of alcohol per hour. During periods of continued drinking, there aren’t enough enzymes to metabolise the excess alcohol, leading to increased exposure to acetaldehyde.5 

Although acetaldehyde only exists for a short time before it is further broken down, it can cause significant damage to cells. This process can lead to liver disease and cancer.5, 6

Talk to your doctor to find out if your drinking might be impacting your liver health. Stopping drinking may help to reverse or slow down early signs of alcohol-related liver disease. 

Stages of alcohol-related liver disease

Learn more about the stages of liver disease caused by alcohol and how this can lead to cancer.5

  • Fatty liver disease (steatosis) is the earliest and most common form of liver disease caused by alcohol. 
  • A healthy liver contains very little or no fat. The build up of fat in liver cells makes it hard for the liver to function.
  • Fatty liver can happen without causing any symptoms, meaning it can sometimes go undetected or undiagnosed for years.
  • Even without symptoms, ongoing inflammation caused by fat in the liver can lead to serious complications, including inflammation (hepatitis) and scarring (cirrhosis). 
  • The damage from fatty liver disease may be reversed if diagnosed early.

  • Alcohol-related hepatitis is when the liver becomes inflamed and swollen.
  • Symptoms include fever, nausea, vomiting, abdominal pain, tenderness and jaundice. 
  • Alcohol-related hepatitis can occur suddenly after heavy drinking (acute hepatitis) or develop gradually over years (chronic hepatitis). Both cause liver damage and can lead to serious health problems, including cirrhosis, liver cancer, and death.

  • Cirrhosis is a long-term liver condition that most commonly develops as a result of chronic liver inflammation (hepatitis).
  • It is the most severe form of liver disease and occurs when cells in the liver are damaged and replaced with scar tissue.
  • Scar tissue prevents the liver from filtering toxins and waste products out of the body, effectively stopping the liver from working normally. 
  • Symptoms include build up of fluid in the abdomen, high blood pressure, swelling, confusion and easily bruising and bleeding. 
  • Cirrhosis is a major risk factor for liver cancer (hepatocellular carcinoma) and it can also cause the liver to stop working (known as liver failure), which can lead to death. 

  • When the liver breaks down alcohol, it is converted to acetaldehyde, a highly toxic chemical and Group 1 carcinogen. 
  • Acetaldehyde damages cells by binding with DNA and causing cells to replicate incorrectly. The more cells in the liver try to repair the damage, the more likely they can make mistakes in their DNA, which can lead to cancer.
  • The risk of developing liver cancer is higher with pre-existing cirrhosis (scarring).

Learn more about alcohol and cancer

Reduce your risk of harm

If you drink, the Australian Alcohol Guidelines recommends no more than 10 standard drinks per week and no more than 4 standard drinks on any day to reduce the risk of alcohol-related harm. 

The less you drink, the lower your risk of harm from alcohol.

Tips to reduce your drinking

  1. Paton A. Alcohol in the body. 2005. BMJ. Jan 8;330(7482):85-7. doi: 10.1136/bmj.330.7482.85.
  2. Hyun J, Han J, Lee C, Yoon M, Jung Y. Pathophysiological Aspects of Alcohol Metabolism in the LIver. 2021. Int J Mol Sci. May 27;22(11):5717.doi:10.3390/ijms22115717.PMID:34071962;PMCID:PMC8197869
  3. Rajendram, Roshanna, Rajendram, Rajkumar and Preedy, V.R. Acetaldehyde. 2016. Neuropathology of Drug Addictions and Substance Misuse, pp. 552–562. doi:10.1016/b978-0-12-800213-1.00051-1
  4. International Agency for Research on Cancer. 2012. Personal habits and indoor combustions. IARC.
  5. Patel R, Mueller M. Alcoholic Liver Disease. 2022. Alcoholic Liver Disease. StatPearls Publishing; 2023 Jan. Available from:
  6. Connor J. Alcohol consumption as a cause of cancer. 2017. Addiction. Feb;112(2):222-228. doi: 10.1111/add.13477.

Page last updated7 August 2023