The main function of the liver is to process and process various substances taken from outside the body or produced in the body, synthesize important substances and provide them to the organism. The liver is equivalent to an industrial park with various energy and chemical plants. In addition, the liver has functions such as storing blood and participating in immunity. Therefore, once the liver function is drastically low, many abnormal problems can occur. Specific liver functions are as follows: 1. Processing the ingested substances into necessary substances or nutrients according to the body’s needs Ingested food is digested and absorbed in the gastrointestinal tract, carbohydrates are broken down into glucose, fats are broken down into fatty acids and cholesterol, proteins are broken down into amino acids and absorbed, vitamins with small molecular weight, organic and inorganic substances can be absorbed directly. These substances first run to the liver, either directly stored, or converted into other substances to be transported to other organs 2, synthesis of essential proteins and compounds In the human serum 100 ml contains 6-8g of protein, of which about 90% is synthesized in the liver. The liver synthesizes up to 15-50 g of proteins a day, represented by albumin and coagulation substances. When there is cirrhosis of the liver there may be bleeding tendencies such as nosebleeds or dental bleeds, which are caused by the lack of proteins necessary for blood clotting. 3.Metabolism and excretion of various drugs Various drugs that enter the body are transformed into other substances in the liver, and their functions are changed, and they are transformed into forms that can be excreted and excreted through urine or bile. Alcohol is also metabolized and broken down in the liver. This detoxification effect is especially important for patients with liver disease, because the indiscriminate use of drugs can make the drug itself or metabolites directly toxic effects on the liver. 4. Detoxification After protein metabolism in the liver, toxic substances called ammonia are produced, while the liver converts ammonia into urea to prevent ammonia from accumulating in the body. When the liver fails, it will lead to the accumulation of ammonia and “hepatic encephalopathy”. The liver converts absorbed glucose into a large molecule called hepatic glycogen, which is stored in the liver. When the body is deficient in glucose, it is broken down and excreted into the bloodstream. Occasionally, glucose is synthesized from amino acids to provide energy. In the human body glucose acts as a fuel like gasoline, participating in the activities of the body, the brain and the most basic cellular life activities. That is, the liver plays an important role in providing and regulating energy to all parts of the body. 6.The role of secretion and excretion of bile Bile is an important substance for digestion and absorption of fat, and at the same time is a channel for excretion of various substances. After the red blood cells are destroyed, part of them are turned into bilirubin and excreted by bile. When bile secretion and excretion are impaired, bilirubin will accumulate in the body, resulting in jaundice and impaired fat digestion. 7.Maintain the balance of hormones in the body Hormones are synthesized in the endocrine organs to regulate various body functions in trace amounts. Most hormones undergo chemical changes in the liver and are excreted. For example, thyroid hormone, estrogen, aldosterone and antidiuretic hormone are metabolized in the liver. Therefore, when liver disease is severe, imbalances in hormone levels can occur, affecting the normal function of the body. A certain level of each hormone is maintained in the blood, and the excess is processed by the liver to lose its activity. When suffering from liver disease, the inactivation of the above hormones may be impaired and the corresponding abnormal symptoms may occur. Vitamins A, D, B12, etc. are stored in the liver. Therefore, even without vitamin supplementation, vitamin A can last for 10 months, vitamin D for 3-4 months, and vitamin B12 for more than 1 year. Iron is an important component of hemoglobin, and the liver stores more iron than the entire blood in the body contains. 9, plays the role of blood storage bank Normally, the liver contains about 450 ml of blood, equivalent to 10% of the total blood volume. The liver has a strong regenerative capacity, and when there is too much blood in the body, the role of the excess blood temporarily placed in the liver. Conversely, when the amount of blood is insufficient there is a role in providing blood. 10, has a defensive role in the large intestine in the growth of a large number of bacteria, from the colon into the liver in the blood may contain such bacteria. However, bacteria are rarely detected in the blood circulating throughout the body, because they are filtered in the liver. This is the result of phagocytosis in the liver. After these bacteria are filtered by the liver, less than 1% of the bacteria that originally entered the liver leave the liver.