Cirrhosis - Causes of cirrhosis

There are many different causes of cirrhosis. In the UK, the most common causes are drinking excessive amounts of alcohol and long-term hepatitis C infections.

In some cases, no specific cause is identified.

Alcohol consumption

The liver breaks down toxins (poisons), such as alcohol, but too much alcohol can scar and damage it's cells. Men who drink more than 21 units of alcohol a week and women who drink more than 14 units of alcohol a week are considered to be drinking too much. 

Read more about how to track your drinking.

If you're a heavy drinker, your chances of developing cirrhosis are increased. However, it's important to realise that cirrhosis of the liver isn't just a condition that affects people dependent on alcohol. If you're a heavy social drinker, you can also develop cirrhosis.

Alcohol-related cirrhosis usually develops after 10 or more years of heavy drinking. For unknown reasons, some people are more susceptible to liver cell damage than others. Women who drink heavily are more susceptible to liver damage than men, partly because of their different body size and build.

Stages of alcoholic liver damage

People who drink excessively and continue to drink heavily develop cirrhosis in three separate stages. These are described below.

• The first stage of alcohol-related liver disease is known as ‘fatty liver’, which almost all excessive drinkers develop. It is a side effect of the liver breaking alcohol down. It disappears when you drink less.
• The second stage of alcohol-related liver disease is alcoholic hepatitis. Around 20-30% of people who continue to drink heavily develop alcoholic hepatitis. During this stage, the liver becomes inflamed. If alcoholic hepatitis deteriorates into its most extreme form (liver failure) it can lead to death.
• About 10% of heavy drinkers develop cirrhosis, which is the third stage of alcohol-related liver disease.

This risk of developing cirrhosis, along with the risk of alcoholic hepatitis, is one of the main reasons the government recommends that men shouldn't regularly drink more than 3-4 units of alcohol a day, and women shouldn't drink more than 2-3 units of alcohol a day.

Hepatitis

Hepatitis is inflammation of the liver. Left untreated, it can damage the liver over many years, eventually resulting in cirrhosis.

In the UK, the most common form of hepatitis is hepatitis C. The hepatitis C virus is usually transmitted through blood-to-blood contact, most commonly by sharing needles used to inject drugs.

Two other forms of the infection, hepatitis B and D, can also cause cirrhosis.

Non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a severe liver condition that can lead to cirrhosis. As with alcohol-related liver disease, the early stage of NASH is the build-up of excess fat in the liver. This fat is associated with inflammation and scarring, which could lead to cirrhosis.

NASH can develop in people who are obese, have diabetes, have high levels of fat in the blood (high cholesterol) and high blood pressure. Most people with NASH feel well and aren't aware they have a problem until cirrhosis occurs and liver function is affected.

Other causes

A number of other conditions and inherited diseases can prevent the liver functioning healthily and can lead to cirrhosis. These include:

• autoimmune liver disease – the immune system usually makes antibodies to attack bacteria and viruses; however, if you have an autoimmune disease, such as autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis (PSC), your immune system will make antibodies that attack healthy organs
• some rare, genetic conditions – such as haemochromatosis (a build-up of iron in the liver and other parts of the body) and Wilson's disease (a build-up of copper in the liver and other parts of the body)
• any condition that causes the bile ducts to become blocked – such as cancer of the bile ducts or pancreatic cancer 
• Budd-Chiari syndrome – caused by blood clots blocking the veins that carry blood from the liver

Less commonly, the use of certain medications, such as amiodarone and methotrexate, can also cause cirrhosis.