Hepatitis A is an acute viral hepatitis infected through eating or drinking contaminated food and water.

Chronic hepatitis B is an inflammation of the liver caused by the hepatitis B virus which can be acute or chronic. In Hong Kong population, about 8-10% of people are infected with the hepatitis B virus. Chronic hepatitis B is the common cause of cirrhosis and liver cancer.

Hepatitis C is the inflammation of the liver caused by the hepatitis C virus. In Western countries, hepatitis C is a common cause of cirrhosis and liver cancer, but it is not common in Asia. According to a local survey, about 0.5% of the Hong Kong population is infected with hepatitis C virus.

Hepatitis E is an acute viral infection of the liver. Routes of infection include eating or drinking contaminated food and water. Direct person to person contact is a relatively rare transmission route.

Related Information:

Center for Liver Health, The Chinese University of Hong Kong

Autoimmune hepatitis (AH) is the self-induced hepatitis caused by body's immune system attacking the liver cells. The majority of patients aged 15-40 years old, of which about 70% are women. Autoimmune hepatitis is a rather serious illness and is usually chronic in nature which can last for several years throughout the course of the disease. Without proper treatment, the disease may eventually lead to cirrhosis or even liver failure.

Most patients with autoimmune hepatitis have no symptoms, only a small portion of patients will have fatigue, abdominal discomfort, nausea, loss of appetite, jaundice, hepatomegaly, dark urine and lighter stool color etc. In serious case, ascites may be occurred.

Fatty liver is a condition that excessive fat accumulates in the liver cells, and its content exceeds 10% by weight of the liver. Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease that is closely related to metabolic diseases such as diabetes, hypertension, hyperlipidemia and obesity. Its characteristic is very similar to that of alcoholic fatty liver, but it occurs in people with little or no alcohol consumption. In developed countries, non-alcoholic fatty liver disease has become one of the most common chronic liver diseases which about 20% of the population are affected.

Cirrhosis is caused by repeated liver damage resulting in liver atrophy and structural damage. Generally speaking, some of the injured liver cells will die after damaged, but the liver cell can be regenerated, so that the injured part can be healed. However, if there is chronic and continuous liver damage, some of the damaged areas will have scars. Because the scar tissues do not have any function, too many scars will affect the normal function of the liver, resulting in cirrhosis eventually. Cirrhosis can cause a series of complications and may develop into cancer. Chronic hepatitis B, chronic hepatitis C and alcoholic liver disease are the common causes of cirrhosis.

Liver cancer here is talking about the primary liver cancer. Liver cancer caused by proliferation of tumor from other parts of the body is called the liver metastatic tumors. Because hepatitis B is very common in Hong Kong, and hepatitis B may increase the risk of having liver cancer, liver cancer is the fourth most common cancer in Hong Kong and the mortality rate ranked third among various cancers.