1. Laboratory tests (1) Blood count Hemoglobin (hematocrit), platelets, and white blood cell count are reduced. (2)Liver function test Mild abnormality in compensated stage, decreased serum protein, increased globulin and A/G inversion in decompensated stage. Prothrombin time is prolonged and prothrombin activity is decreased. Transaminases and bilirubin are elevated. Total cholesterol and cholesterol lipids are decreased and blood ammonia may be elevated. Amino acid metabolism is disturbed and the branching/aromatic ratio is imbalanced. Urea nitrogen and creatinine are elevated. Electrolyte disorders: low sodium, low potassium. (3) Pathogenic examination Positive for HBV-M or HCV-M or HDV-M. (4) Immunological examination Immunoglobulins IgA, IgG, IgM may be elevated. Autoantibodies Anti-nuclear antibody, anti-mitochondrial antibody, anti-smooth muscle antibody, and anti-lipoprotein membrane antibody may be positive. Other immunological examinations Decreased complement, decreased roseola node formation rate and lytic turnover rate, decreased CD8(Ts) cells, and decreased function. (5) Fibrotic examination PIIIP value is increased, prolyl hydroxylase (PHO) is increased, monoamine oxidase (MAO) is increased, and serum laminin (LM) is increased. (6) Peritoneal fluid examination Those with newly developed peritoneal fluid or those with rapid increase of existing peritoneal fluid for unknown reasons should undergo laparotomy and draw peritoneal fluid for routine examination, adenosine deaminase (ADA) determination, bacterial culture and cytological examination. In order to improve the culture positivity rate, abdominal fluid culture sampling operation should be performed at the bedside, using blood culture bottles and doing aerobic and anaerobic bacteria culture respectively. 2.Imaging examination (1)X-ray examination Barium esophagogastric-fundus angiography, which shows worm-like or earthworm-like venous varices changes in esophagogastric-fundus veins. (2) B-mode and color Doppler ultrasonography Thickened liver peritoneum, unsmooth liver surface, enhanced echogenicity of liver parenchyma, roughness and disproportion, widened portal vein diameter, splenomegaly, and fluid accumulation in the abdomen. (3) CT examination Distorted ratio of liver lobes, reduced density, nodule-like changes, widened hilum, splenomegaly, and fluid accumulation in the abdominal cavity. 3.Endoscopy (invasive and risky) can determine the presence of esophagogastric fundic varices, the positive rate is higher than that of barium meal X-ray, and it can also understand the degree of varices and assess the risk of bleeding. Esophago-gastric varices are the most reliable indicator for the diagnosis of portal hypertension. In case of complicated upper gastrointestinal bleeding, emergency gastroscopy can determine the site and cause of bleeding and provide hemostatic treatment. 4.Liver biopsy examination (invasive and risky) Liver aspiration biopsy can confirm the diagnosis. 5.Laparoscopy is rarely used at present. It can directly observe the liver, spleen and other abdominal organs and tissues, and biopsy can be taken under direct vision, which is valuable for those who have difficulty in diagnosis. 6.Portal vein pressure measurement At present, it is rarely used. The difference between wedge pressure and free pressure of hepatic vein is hepatic vein pressure gradient (HVPG), which reflects portal vein pressure. Normal is less than 5 mmHg, and greater than 10 mmHg is portal hypertension.