Human serum albumin is a protein in human plasma that is synthesized mainly by the liver. Albumin is the main protein component of normal human serum, synthesized by the liver at about 120 mg/kg per day, with a half-life of 15-19 days and a molecular weight of 66 KD, and belongs to the non-acute time-phase proteins. 1.Human serum albumin plays an important role in the maintenance of plasma colloid osmotic pressure and the transportation of metabolic substances in the body. 2. The normal reference value of human serum albumin is 20-40g/L. If there is a decrease, it suggests the possible existence of liver diseases, such as hepatitis, cirrhosis and liver cancer. If the serum albumin concentration of the body is lower than 25g/L, the colloid osmotic pressure of the body will decrease, and then the water inside the blood vessels will seep outside the blood vessels, leading to the emergence of tissue edema. 3. However, there are also cases of elevated or pseudo-elevated human serum albumin, which are commonly seen in concentrated dehydration and profuse sweating. Individuals with abnormal serum albumin levels should be referred to their physician for further testing and treatment.