A heterogeneous group of diseases that are of particular importance because of the many essential functions of the liver. Persons with liver disorders can develop a number of different signs and symptoms. One common symptom is fatigue, although some people are entirely asymptomatic. A striking sign of liver disease is jaundice (yellowing of the skin and eyes) due to abnormal production or transport of bile. The presence of liver disease can be confirmed by performing liver function tests on the blood. A needle biopsy can help determine the type of liver disorder and the extent of organ damage. See also Jaundice; Liver.
Fatty metamorphosis is a common condition characterized by accumulation of fat (lipid) within the liver cells. In the United States the most common cause of a fatty liver is excessive alcohol intake. In the developing areas of the world, malnutrition is the major cause of a fatty liver. Some obese persons also develop a fatty liver. See also Alcoholism; Malnutrition; Obesity.
Hepatitis, an inflammation of the liver, has a variety of causes. The specific type of hepatitis present is usually determined by studies of serum, which identify the type of antibody directed against a component of the causative virus, or by liver biopsy. See also Hepatitis.
Cirrhosis is a disease in the liver characterized by scarring, which produces a marked nodularity of the liver. Cirrhosis has a variety of causes, although in the United States the most common by far is excessive alcohol intake. Cirrhosis may also result from almost any type of injury to the liver that does not heal but instead leads to progressive inflammation and scarring. See also Cirrhosis.
Most neoplasms in the liver are malignant and are metastatic from a primary site. Usually their cause is unknown, but in the United States primary malignant tumors are most frequently associated with cirrhosis. Primary liver cancers are difficult to treat because they usually grow rapidly and involve other structures, preventing total surgical removal. See also Cancer (medicine); Oncology.
Reye's syndrome is a liver disorder that affects primarily infants and young children; it usually occurs during or after an episode of viral influenza and it has been causally related to the ingestion of aspirin for treatment of influenza. Wilson's disease, also called hepatolenticular degeneration, is a rare inherited disorder of copper metabolism in which cirrhosis of the liver is associated with degeneration of certain regions of the brain. Hemochromatosis, another hereditary disease, is marked by excessive deposition of iron in the liver because of faulty iron metabolism. It causes cirrhosis and is frequently associated with primary cancer of the liver. In alpha-1 antitrypsin deficiency, a disease characterized by an absence of an antienzyme in the blood, the liver can show extensive fibrosis and even cirrhosis.
