First, a causal relationship between chronic HBV infection and liver disease should be established and the severity of liver disease needs to be assessed. In addition, all first-degree relatives and sexual partners of patients with chronic HBV infection should be advised to test for HBV serum markers (HBsAg, anti-HBc, anti-HBs) and to get vaccinated if these markers are negative. Not all patients with chronic HBV infection have persistent transaminase elevations. Patients in the immune tolerance phase and inactive. ALT levels may remain normal in sexual carriers, and a proportion of HBeAg-negative CHB patients may have intermittently normal A L T levels. Therefore, appropriate longitudinal long-term follow-up is essential. (1) Assessment of the severity of liver disease should include: biochemical indicators including glutamic aminotransferase (AST ) and ALT, gamma-glutamyl transpeptidase (GGT), alkaline phosphatase, bilirubin, and serum albumin and globulin, blood count and prothrombin time, and liver ultrasound. Normally, ALT levels are higher than AST, however, this ratio can be inverted as the disease progresses to cirrhosis. A gradual decrease in serum albumin concentration and/or an increase in (gamma-)globulin, as well as a prolonged prothrombin time, often accompanied by a decrease in platelet count, are characteristic observations after the development of cirrhosis. (2) HBV DNA testing and HBV DNA level determination are the basis for patient diagnosis, treatment decisions and subsequent monitoring. Because of its sensitivity, specificity, accuracy and wide dynamic range, the use of real-time PCR quantitative analysis for follow-up is highly recommended. The World Health Organization (WHO) has developed international standards for the standardized expression of HBV DNA concentrations. Serum HBVDNA levels are expressed using IU/ml to ensure comparability. The same method should be used to assess the efficacy of antiviral therapy in the same patient. IU/ml is used for all HBV DNA units in the manuscript, and copy/ml is IU/ml multiplied by 5. (3) Other etiologies of chronic liver disease should be systematically examined, including co-infection with HDV, HCV, and/or HIV (A1); patients with chronic HBV infection should also be tested for hepatitis A virus-associated antibodies (anti-HAV), and if anti-HAV is negative, HAV vaccination is recommended. Comorbidities should also be evaluated, including metabolic liver disease such as alcoholic, autoimmune, fatty liver or steatohepatitis. (4) Liver biopsy is often recommended to clarify the severity of inflammatory necrosis and fibrosis, due to the fact that liver histology helps determine whether to initiate treatment. Indications for liver biopsy are described in the indications for treatment. Liver biopsy is also useful in evaluating other causes of liver disease such as fatty liver disease. Although liver biopsy is an invasive procedure, the incidence of serious complications is very low (1 in 4000-10000). It is important that the needle aspiration biopsy sample be large enough to accurately assess the severity of liver damage, especially fibrosis. Patients with clinical evidence of cirrhosis or clear indications for treatment without consideration of activity grading and fibrosis staging usually do not require liver biopsy. Currently, there is a growing interest in non-invasive methods, including serum markers and transient elastometry, in the assessment of liver fibrosis as a complement to or to avoid liver biopsy. In Europe, transient elastometry is a widely used non-invasive method to detect cirrhosis with high diagnostic accuracy, although severe inflammation associated with high ALT levels can confound the results and the optimal threshold for liver elastometry varies among studies.