Hepatitis B virus infection mostly has no precursor manifestations, and the initial symptoms are atypical, with symptoms such as generalized weakness and easy fatigue. If hepatitis B virus infection does not occur, patients often do not have typical symptoms, the initial symptoms of generalized weakness, fatigue, etc., followed by anorexia and bloating, nausea and other gastrointestinal symptoms. Hepatitis B virus is a hepatophilic DNA virus, consisting of an envelope and a nuclear shell, which is highly contagious and mainly invades the human liver, leading to hepatitis B, liver fibrosis, liver cancer and other related diseases. Because patients with hepatitis B virus infection are asymptomatic in most cases, most people are unaware that they are infected with the hepatitis B virus and usually find out through a physical examination or routine hospitalization. If you suspect that you are infected with the hepatitis B virus, you can go to the hospital for tests such as the hepatitis B two-pair test, DNA of the hepatitis B virus, and liver function.