Chronic liver disease starts with understanding hepatitis

Author: Yan Liping, Fifth Medical Center, PLA General Hospital

Reviewer: Jin Bo, Chief Physician, Fifth Medical Center, PLA General Hospital

The liver plays an important role in the life activities of the body. It is located in the upper right abdomen. It is the largest gland in the human body and the largest solid organ. It not only participates in the metabolism of nutrients such as sugar, fat, and protein, but also participates in the detoxification of harmful substances such as drugs, ethanol (alcohol), and poisons. In addition, the liver also secretes bile and participates in hematopoiesis and coagulation. Therefore, once there is a problem with the liver, our health will be greatly affected. Next, we will lead you to have a deep understanding of the relevant knowledge of hepatitis in order to curb the occurrence and development of chronic liver disease.

1. What is the “trilogy” of chronic liver disease?

Viruses, alcohol, drugs, metabolic or autoimmune abnormalities can invade the liver, causing liver cell damage and liver function impairment. Acute hepatitis cases are not cured and turn into chronic hepatitis; chronic hepatitis continues to progress under the continuous action of pathogenic factors or the participation of the body's immune response, gradually forming liver fibrosis and cirrhosis, and some cases even progress to liver cancer. This is the "trilogy" of liver disease: hepatitis-cirrhosis-liver cancer.

Figure 1 Copyright image, no permission to reprint

2. What is hepatitis?

Hepatitis is a general term for liver inflammation caused by various reasons. It usually refers to the invasion of the liver by multiple pathogenic factors (such as viruses, bacteria, parasites, drugs and poisons, alcohol) and autoimmune factors, which damage liver cells, impair liver function, and cause a series of physical discomfort symptoms and abnormal liver function indicators.

According to the course of the disease, hepatitis can be divided into acute hepatitis (course of disease does not exceed 6 months) and chronic hepatitis (course of disease lasting more than 6 months).

Figure 2 Copyright image, no permission to reprint

3. What types of hepatitis can be classified according to their causes?

1. Viral hepatitis: It is the most common type of hepatitis in my country. It is caused by hepatitis virus and is a group of infectious diseases characterized by liver inflammation and necrosis. Viral hepatitis is divided into hepatitis A, hepatitis B, hepatitis C, hepatitis D, and hepatitis E. Among them, the main transmission routes of hepatitis B, C, and D are vertical transmission, blood transmission (blood transfusion, acupuncture, drug abuse, etc.) and sexual transmission, while the main transmission route of hepatitis A and E is fecal-oral transmission.

2. Alcoholic hepatitis: It is liver damage caused by long-term heavy drinking. The patient has a long-term drinking history, generally drinking for more than 5 years, and the alcohol intake is ≥40 g per day for men and ≥20 g per day for women, or has a history of heavy drinking within 2 weeks, and the alcohol intake is >80 g per day.

3. Toxic hepatitis: It is liver damage caused by long-term use of certain drugs or long-term repeated exposure to certain chemical poisons. It can occur in healthy people with no history of liver disease or in patients with other underlying diseases.

4. Fatty hepatitis: Liver damage caused by excessive fat accumulation in liver cells due to various reasons, such as alcoholism, high blood lipids, and overweight.

5. Metabolic hepatitis: Liver damage caused by poor metabolism of certain substances in the body, such as copper, tyrosine, etc.

6. Cholestatic hepatitis: It is caused by various reasons that cause bile secretion disorders in hepatocytes and/or bile duct capillaries, leading to partial or complete cholestasis. It often occurs several weeks after the onset of acute hepatitis.

7. Immune hepatitis: refers to chronic progressive liver inflammation mediated by autoimmune response, and its etiology is not yet fully understood. Genetic susceptibility is considered to be the main factor causing immune hepatitis, while other factors may cause the destruction of the body's immune tolerance mechanism on the basis of genetic susceptibility, resulting in immune responses against liver autoantigens, thereby destroying liver cells and causing liver inflammation and necrosis, which is common in women.