The most common cases of high immunoglobulin IgG in blood are: i. High immunoglobulin IgG caused by autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, dry syndrome, leukoaraiosis and so on. To confirm the cause, you need to go to the hospital to check the blood routine, blood sedimentation, anti-nuclear antibody profile, anti-double-stranded DNA, etc. After the diagnosis is confirmed and then give symptomatic treatment, the high immunoglobulin IgG will be gradually reduced. If IgG is obviously high and other immunoglobulins are reduced, this is most likely to be multiple myeloma, and the patient may have kidney damage, bone pain, etc. in addition to high IgG. After diagnosis, chemotherapy, such as lenalidomide and bortezomib, will be administered and the high IgG will be gradually reduced to normal.