Both hepatitis B virus infection and alcohol consumption can cause liver damage, but the sites and mechanisms of liver damage are different between the two. Both persistent or recurrent hepatitis activity and long-term, heavy alcohol consumption can eventually lead to cirrhosis, liver failure and hepatocellular carcinoma; therefore, people with hepatitis B virus infection should take alcohol consumption seriously. Let’s first introduce hepatitis B virus infection. Hepatitis B virus infection can be classified as self-limited or persistent depending on how long the virus has been present in the body; if an infected person develops hepatitis-related symptoms such as malaise, loss of appetite or yellowish skin and/or elevated serum alanine aminotransferase, this is called hepatitis B. Hepatitis due to self-limiting infection is usually referred to as acute hepatitis B. Hepatitis due to persistent infection is generally referred to as chronic hepatitis B. Whether acute or chronic hepatitis B, if the disease is severe enough to be life-threatening, it is referred to as severe hepatitis; patients with severe hepatitis do not have a drinking problem and are not part of the discussion in this article. In about 70% to 80% of acute hepatitis B and almost 100% of chronic hepatitis B, the main site of damage to the liver is around the confluent area, which is a concentration of small blood vessels and small bile ducts within the liver tissue, where the small vessels refer to the smallest branches of the portal vein and hepatic artery, called the terminal portal vein and terminal hepatic artery, respectively. The subbranches of the terminal portal vein and the terminal hepatic artery are the hepatic sinusoids, which are similar to capillaries in other organ tissues and are in “direct” contact with hepatocytes; the sinusoids then merge to form the terminal hepatic vein, which is equivalent to small veins in other organ tissues. It is important to note that blood from the portal vein is rich in nutrients, while blood from the hepatic artery has the highest oxygen content; the direction of blood flow in liver tissue is from the terminal portal vein and the terminal hepatic artery through the hepatic sinusoids into the terminal hepatic vein. Therefore, the main site of damage in hepatitis B is a relatively “nutrient-rich and oxygen-rich” area, where damaged liver cells are relatively easy to repair. The next step is to describe the metabolism of alcohol or ethanol and its accompanying liver damage. When alcohol is consumed, a small percentage is exhaled directly by the lungs and excreted directly by the kidneys; most of it needs to be metabolized in the liver and eventually converted into acetic acid, a substance that provides energy. Hepatocytes, mainly around the terminal hepatic veins away from the confluent area, are the main site of ethanol metabolism. Under the action of ethanol dehydrogenase, cytochrome P450 or peroxidase, mainly ethanol dehydrogenase, ethanol is converted to acetaldehyde and accompanied by the production of large amounts of reactive oxygen radicals. In the presence of acetaldehyde dehydrogenase, acetaldehyde is converted to acetic acid that can be used by other tissues. Acetaldehyde has the effect of inhibiting fatty acid oxidation, leading to the accumulation of fatty acids in hepatocytes, and reactive oxygen radicals can cause the effect of lipid peroxidation, leading to structural damage and dysfunction of cell membranes. It is important to emphasize that the main site of ethanol-induced liver injury is the relatively “nutrient and oxygen depleted” region, where damaged hepatocytes are relatively difficult to repair. There is no doubt that chronic heavy alcohol consumption, with or without hepatitis B virus hepatitis, is bound to cause liver damage. In fact, the ability of humans to metabolize ethanol varies greatly, and the terms “chronic” and “heavy” are relative; the liver has considerable reserve function and repair capacity, and occasional or moderate alcohol consumption does not usually result in serious liver problems. The hepatitis B virus infection and alcohol consumption Since both hepatitis B virus infection and alcohol consumption can cause liver damage, people with hepatitis B virus infection need to be cautious about alcohol consumption and not drink as much as possible. Specifically, patients with acute hepatitis B should not drink alcohol, and patients with acute hepatitis B should not drink alcohol within 6 months after recovery because it takes 6 months for the liver to repair after hepatitis; chronic hepatitis B active period, whether “major triple-positive” or “minor triple-positive “Patients diagnosed with hepatitis B-related cirrhosis should not drink alcohol; chronic hepatitis B virus-infected patients with fatty liver, whether or not they are in active hepatitis, should not drink alcohol; patients taking nitroimidazoles such as metronidazole, tinidazole and cephalosporins for other diseases should not drink alcohol; chronic hepatitis B virus-infected patients with chronic gastrointestinal diseases or kidney diseases should not drink alcohol. Patients with chronic hepatitis B virus infection who have a combination of chronic gastrointestinal or kidney disease should also not drink alcohol. However, chronic hepatitis B virus infection called “carriers” who have been followed up regularly for more than one year, examined every three months, and whose liver function serum alanine aminotransferase and blood platelet count are within the normal reference range, as well as whose liver, spleen and gallbladder are not abnormally described by ultrasound examination, may occasionally drink alcohol in moderation. It should be noted that if a “carrier” accidentally consumes large amounts of alcohol or develops symptoms related to hepatitis after drinking alcohol, it is best to consult a specialist in a timely manner to check liver function and let the doctor determine whether it is hepatitis activity or alcohol damage.