Causes
Hepatitis is an inflammation of the liver that can be caused by a virus,
inherited disorders, and sometimes by certain medications or toxins such as
alcohol and drugs. Scientists have identified three main types of viral
hepatitis: hepatitis A, hepatitis B, and hepatitis C.
Hepatitis A is waterborne and spread mainly via sewage and contaminated
food and water. Hepatitis B is transmitted by contact with infected semen,
blood, vaginal secretions and from mother to newborn. Hepatitis B is most commonly
spread by unprotected sex and by sharing of infected needles, although certain
populations (e.g., health workers) are at higher risk for the infection as well.
Hepatitis C spreads via direct blood-to-blood contact. Improved screening
of donated blood has greatly reduced risk of catching hepatitis B or C from
blood transfusions.
The main cause of cirrhosis is chronic infection with the hepatitis C virus.
Other causes include:
- long-term, excessive alcohol consumption
- chronic infection with hepatitis B virus
- inherited disorders of iron and copper metabolism
- severe reactions to certain medications
- infections from bacteria and parasites usually found in the tropics
- repeated episodes of heart failure with liver congestion and bile-duct obstruction
With cirrhosis, the liver tissue is irreversibly and progressively destroyed
as a result of infection, poison or some other disease. Normal liver tissue
is replaced by scars and areas of regenerating liver cells.