Interleukin-6 is mainly produced by Th2 cells and secreted by T lymphocytes, B lymphocytes, fibroblasts, endothelial cells, keratinocytes, hepatocytes and bone marrow cells. Its relative molecular weight is 26kDa. It is a glycoprotein composed of 212 amino acid residues. Interleukin-6 is the first biomarker to appear after inflammatory reaction. In different inflammatory diseases, the content of interleukin-6 is significantly different. The increased level of interleukin-6 caused by bacterial infection is significantly higher than that caused by non-bacterial infection, and the level of interleukin-6 is directly proportional to the severity of inflammation and infection. Interleukin-6 is also a sensitive early warning index of sepsis, and has a good correlation with the severity and prognosis of sepsis. As an inflammatory factor, the level of interleukin-6 is also closely related to cardiovascular and cerebrovascular diseases such as atherosclerosis and acute myocardial infarction (AMI).