Cirrhosis is severe scarring of the liver caused by chronic liver disease. As healthy liver tissue is damaged over a long period of time, it is replaced by scar tissue, affecting the structure of the liver and decreasing its ability to function. Cirrhosis is seen with a variety of chronic liver diseases and may take years or even decades to develop. Unlike scars in other parts of the body, some of the scarring that occurs in the liver is reversible, even in people with cirrhosis; it is difficult to tell which scars can be removed and which will be permanent.
The liver is a vital organ located in the upper right-hand side of the abdomen. Among other functions, it helps convert nutrients from food into essential blood components, produces many of the factors necessary for normal blood clotting, metabolises and detoxifies substances that would otherwise be harmful to the body, and produces bile – a fluid necessary for the digestion of fats.
Liver diseases can affect any of these critical functions. These diseases may be the result of infection, injury, exposure to a toxin, an autoimmune process, or due to a genetic defect that leads to the build-up of substances such as copper or iron. The damage that liver diseases cause can lead to inflammation, obstruction,and clotting abnormalities. Prolonged and persistent damage can lead to the accumulation of excess connective tissue, or fibrosis of the liver. Fibrosis can lead to cirrhosis.
With cirrhosis, the structure of the liver changes, forming nodules of cells surrounded by fibrous tissue. This tissue does not function like healthy liver tissue and can interfere with the flow of blood and (rarely) bile through the liver. As cirrhosis progresses, it can begin to affect other organs and tissues throughout the body. Some examples of these effects and complications include:
- An increase in pressure in the vein that carries blood to the liver; this is called portal hypertension.
- Swelling and bleeding of the veins in the oesophagus and/or stomach (oesophageal and/or gastric varices) due to the increased pressure from portal hypertension and the redirection of blood into these smaller veins
- An increase in toxins in the blood, which can cause confusion and other mental changes (hepatic encephalopathy)
- Ascites – a build-up of fluid in the abdomen (peritoneal cavity)
- Kidney dysfunction (hepatorenal syndrome)
- Decline in clotting factor production, which can cause easy bleeding and bruising
Individuals with cirrhosis are also at increased risk of developing liver cancer (hepatocellular carcinoma). This is estimated to occur in 3-5% of patients with cirrhosis each year, and multiple cancers can form over time.