Delayed excretion of bromosulfophthalein is an indicator of abnormal liver function with increased serum alkaline phosphatase activity, delayed excretion of bromosulfophthalein, decreased plasma albumin, prolonged prothrombin time, and elevated indirect bilirubin abnormal globulin. Abnormal liver function is when the liver is damaged by certain pathogenic factors that can cause damage to the morphological structure of the liver and abnormal metabolism of liver function. There are many causes of liver function abnormalities, which can be summarized into the following categories: 1. Infection. Parasites (Schistosoma, Toxoplasma gondii, Amoeba), Leptospira, bacteria, viruses can cause liver damage; especially viruses are the most common (e.g. viral hepatitis). 2, chemical poisoning such as carbon tetrachloride, chloroform, phosphorus, antimony, arsenic agents, etc., can often destroy the enzyme system of hepatocytes, causing metabolic disorders, or inhibit the oxidative phosphorylation process, atp production is reduced, resulting in hepatocyte degeneration and necrosis; some drugs, such as chlorpromazine, para-aminobutyric acid, isoniazid, certain iodine drugs and antimicrobial agents (such as tetracycline), even in therapeutic doses can cause liver damage in a small number of people damage, which may be related to allergy. 3, abnormal immune function liver disease can cause abnormal immune response, and abnormal immune response is one of the important causes of liver damage. For example, both humoral immunity and cellular immunity caused by hepatitis B virus can damage liver cells; surface antigen (hbsag), core antigen (hbcag) and e antigen (hbeag) of hepatitis B virus can bind to the surface of liver cells and change the antigenicity of liver cell membrane, causing autoimmunity. Another example is primary biliary cirrhosis, where patients have a variety of antibodies in their blood (anti-small bile duct antibody, anti-mitochondrial antibody, anti-smooth muscle antibody, anti-nuclear antibody, etc.), which may also be an autoimmune disease. 4.Lack of choline and methionine can cause hepatic steatosis when there is a lack of nutrition. This is because the transport of fat in the liver must be transformed into phospholipids (mainly lecithin), and choline is an essential component of lecithin. Methionine supplies the methyl group for the synthesis of choline. When these substances are lacking, the removal of fat from the liver is blocked, causing fatty changes in the liver. 5.Obstruction of bile duct (such as stone, tumor, roundworm, etc.) causes bile to accumulate, and if the time is too long, it may cause hepatic ischemia due to the damaging effect of stagnant bile on hepatocytes and the compression of blood sinusoid by dilated bile ducts in the liver, which causes hepatocyte degeneration and necrosis. 6, blood circulation disorders such as chronic heart failure, causing liver stasis and hypoxia. 7.Tumor such as liver cancer damage to liver tissue. 8.Genetic defects Some liver diseases are hereditary diseases caused by genetic defects. For example, because the liver can not synthesize copper blue protein, copper metabolism is impaired, and cause liver bean nucleus degeneration; the lack of 1-phosphoglucosyl galactosyl uridyltransferase in liver cells, 1-phosphogalactose can not be transformed into 1-phosphoglucosyl and accumulation occurs, damaging liver cells and causing cirrhosis.