Cirrhosis

Cirrhosis is most often caused by excessive ingestion of alcohol. In the United States, 90% of all cases of cirrhosis are related to alcohol overconsumption. Although researchers still do not have a clear understanding of how alcohol damages the liver, it is thought that consuming more than 1 pint of alcohol (86 proof) daily for 10 years increases the risk of cirrhosis by 10%. The risk of cirrhosis increases to 50% if this consumption lasts 25 years. Women may be more susceptible to alcoholic cirrhosis than men. Women have lower levels of the enzyme alcohol dehydrogenase, which breaks down alcohol in the stomach. Lower levels of this enzyme lead to higher blood alcohol levels.

Researchers believe that the main cause of alcohol-induced cirrhosis is acetaldehyde, the first product created when alcohol is broken down in the stomach. Acetaldehyde combines with proteins in the body and damages the liver cells, leading to fat accumulation and fibrous tissue formation. Further damage to liver cells may be caused by a secondary effect of alcohol on the liver: the acetaldehyde may make the liver cells vulnerable to the potentially damaging effects of substances such as acetaminophen (a common over-the-counter pain reliever), industrial solvents, and certain anesthetics on the liver cells.

Although excessive alcohol intake is considered the leading cause of cirrhosis, there are numerous other causes of the disease. These include several types of viral hepatitis, nutritional factors, genetic conditions, and others. In addition, these are often contributing factors in alcoholic cirrhosis. Chronic infection with hepatitis B virus (HBV) can lead to cirrhosis and is also related to liver cancer.