Hepatic coma; Encephalopathy - hepatic
Hepatic encephalopathy is a worsening of brain function that occurs when the liver is no longer able to remove toxic substances in the blood.
Hepatic encephalopathy is caused by disorders that affect the liver. These include disorders that reduce liver function (such as cirrhosis or hepatitis) and conditions in which blood circulation does not enter the liver. The exact cause of hepatic encephalopathy is unknown.
An important job of the liver is to change toxic substances that are either made by the body or taken into the body (such as medicines) and make them harmless. However, when the liver is damaged, these "poisons" may build up in the bloodstream.
Ammonia, which is produced by the body when proteins are digested, is one of the harmful substances that is normally made harmless by the liver. Many other substances may also build up in the body if the liver is not working well. They can cause damage to the nervous system.
Hepatic encephalopathy may occur suddenly in people who previously had no liver problems when damage occurs to the liver. More often, the condition is seen in people with chronic liver disease.
Hepatic encephalopathy may be triggered by:
Disorders that can mimic or mask symptoms of hepatic encephalopathy include:
Schuppan D, Afdhal NH. Liver cirrhosis. Lancet. 2008;371:838-851.
Munoz SJ. Hepatic encephalopathy. Med Clin North Am. 2008;795-812.
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