High serum β2-microglobulin can be seen in nephritis, lung cancer and other diseases, which can cause renal failure, respiratory failure and other hazards. β2-microglobulin is a kind of small molecule globulin, which is produced by lymphocytes, platelets, polymorphonuclear leukocytes and so on. Its elevated concentration can be seen in acute and chronic nephritis, kidney transplant rejection, liver cancer, lung cancer and other diseases. Acute and chronic nephritis can cause kidney function damage and other hazards, kidney transplant rejection can cause graft failure and other hazards, and liver cancer, lung cancer and other organ malignant tumors can cause liver function or lung function damage. If the above diseases are not intervened in time, further development can cause systemic multi-organ damage or failure, which is life-threatening. The danger of high serum β2 microglobulin is different depending on the cause of the disease. If timely treatment, the above harm can be effectively reduced. Patients with abnormalities in this indicator are advised to seek prompt medical attention.