What is hepatitis?
Hepatitis is an inflammation of the liver that is most commonly caused by viruses but may also be due to chemicals, drugs, alcohol, inherited diseases, or autoimmune disease. The inflammation can be acute, flaring up and then resolving within a few weeks to months, or chronic, enduring over many years. Chronic hepatitis may persist for 20 years or more before causing significant symptoms related to progressive liver damage such as cirrhosis, liver cancer, or death.
The liver is a vital organ located in the upper right-hand side of the abdomen. It performs many functions in the body, including processing the body's nutrients, manufacturing bile to help digest fats, synthesizing many important proteins, regulating blood clotting, and breaking down potentially toxic substances into harmless ones that the body can use or excrete. Inflammation may (in severe cases) interfere with these processes and allow potentially toxic substances to accumulate.
The following table summarizes some common types of hepatitis. Click on the links to read more about the various types.
|Type of Hepatitis||Description||Examples of Causes|
|Viral||Infection with one of the hepatitis viruses causes inflammation; may be acute or chronic depending on virus.||In the US, most common causes are hepatitis A, B and C viruses.|
|Chemical or drug induced||The liver processes many substances for the body to use and/or then eliminate. Some of these substances are toxic to the liver and can result in hepatitis.||Acute or chronic exposure to alcohol, acetaminophen|
|Inherited||Certain gene mutations that are passed from one generation to the next can result in a disease that damages the liver, causing hepatitis.||Wilson disease, hemochromatosis, alpha-1 antitrypsin|
|Non-alcoholic Fatty Liver||Fat deposited in the liver in increasing amounts can lead to decreased amount of healthy liver tissue.||Associated with metabolic syndrome|
|Autoimmune||The body's immune system inappropriately produces antibodies directed against liver tissue.||Associated with type I diabetes, Sjorgren syndrome|