Hepatopulmonary syndrome (HPS) has unknown pathogenesis, limited treatment and poor prognosis. The onset of HPS is insidious and easy to be ignored. Many liver diseases such as "cirrhosis and related complications" are the core characteristics of Beijing You 'an Hospital, but the clinical characteristics of HPS patients in the center are still unclear. The investigators plan to make the diagnosis of HPS among chronic liver disease patients in the hospital according to the diagnostic criteria of HPS proposed in the Practice Guidelines of the International Society of Liver Transplantation in 2016, collect clinical data of HPS participants, evaluate the severity, analyze and summarize clinical characteristics, and conduct management and follow-up. At the same time, The investigators collect blood samples for proteomics tests. In order to improve the diagnosis and treatment level of HPS.

At present, the mechanism of hepatopulmonary syndrome is not clear. The researchers plan to use the extracted plasma for detection, protein extraction and quality control, and then proteolytic hydrolysis, computer detection, and bioinformatics analysis.

Inclusion Criteria:

• chronic hepatitis Agreed to venous blood collection

Exclusion Criteria:

• pneumonia, pulmonary vascular disease, interstitial pulmonary disease, COPD, bronchial asthma, lung cancer and other primary pulmonary diseases, acute upper gastrointestinal bleeding.

Patients with chronic liver disease admitted to You 'an Hospital.