Causes of cirrhosis

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

Insome cases, no specific cause is identified.

Alcohol consumption

The liver breaks down poisons(toxins), such as alcohol, but too much alcohol can scar and damage the liver's cells.

Men and women who drink more than 14units of alcohol a week are considered to be drinking too much.

If you're a heavy drinker, your chances of developing cirrhosis are increased.

Butcirrhosis of the liver isn't just a condition that affects people dependent on alcohol. You can also develop cirrhosis if you're a heavy social drinker.

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:

• first stage known as "fatty liver", which almost all excessive drinkers develop, it's a side effect of the liver breaking alcohol down and disappears when you drink less
• second stage around 20-30% of people who continue to drink heavily develop alcoholic hepatitis; the liver becomes inflamed during this stage, anditcan lead to death if it deteriorates into its most extreme form, liver failure
• third stage cirrhosis, which about 10% of heavy drinkersdevelop

This risk of developing cirrhosis, along with the risk of alcoholic hepatitis, is one of the main reasons the government recommends that men and women should not regularly drink more than 14 units a week.

If you do drink as much as 14 units a week, it's advised that you spread your drinking over three or more days.

A unit of alcohol is roughly equivalent to half a pint of normal-strength lager or a single measure (25ml) of spirits. A small glass of wine (125ml) is about 1.5 units.

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

Inthe UK, Hepatitis C isthe most common form of hepatitis. The hepatitis Cvirusis usually transmitted through blood-to-blood contact, most commonly by sharing needles used to inject drugs.

Two other types of hepatitis 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 peoplewho areobese orhave diabetes ,high levels of fat in the blood (high cholesterol) and high blood pressure .

Most people with NASH feel well and aren't awarethey have a problem until cirrhosis occurs and liver function is affected.

NASH is on the rise in the UK asa result ofincreasing levels of obesity and reduced physical activity. It's likely it will overtake alcohol and hepatitis C as the most common cause of cirrhosis.

Other causes

There are a number of other conditions that can prevent the liver functioning healthily and lead to cirrhosis.

These include:

• autoimmuneliver disease the immune system usually makes antibodies to attack bacteria and viruses, butif 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.