Hepatitis B refers to viral hepatitis B, which is caused by the hepatitis B virus. Clinical manifestations include loss of appetite, nausea, vomiting, fatigue, liver enlargement, abnormal liver function, and some patients may develop fever and jaundice. Some patients with acute hepatitis B will develop into chronic hepatitis B and even heavy hepatitis, cirrhosis and liver cancer. Hepatitis B is mainly transmitted through blood, mother-to-child transmission and sexual contact.1. Blood transmission: Using the same injection tool as a hepatitis B patient, transfusing whole blood, plasma or blood products contaminated with hepatitis B virus may lead to hepatitis B. It can also be transmitted to others through contaminated dental drills, endoscopes, organ transplants and other medical transmission methods.2. Mother-to-child transmission: If the mother is a hepatitis B patient, about 70%-90% of newborns will become hepatitis B without intervention. This is the vertical transmission from mother to child, and the horizontal transmission between mother and child is mainly due to close contact with each other, and the infection of hepatitis B virus during the newborn period is likely to cause long-term or lifelong toxicity; 3, sexual contact transmission: hepatitis B can be transmitted through sexual contact, and when one of the partners has hepatitis B, the other one may also be infected with hepatitis B.