Polyclonal immunoglobulins are immunoglobulins produced by multiple plasma cells. Immunoglobulins are secreted by plasma cells in the body and are classified into various types such as immunoglobulin A, immunoglobulin E, immunoglobulin M, immunoglobulin G, immunoglobulin D, and so on. Normal immunoglobulins can specifically recognize antigens and bind to them, forming antigen-antibody complexes and playing an immune role. Immunoglobulins produced by a variety of plasma cells are polyclonal immunoglobulins. Decreased immunoglobulins may be associated with the use of medications such as immunosuppressive drugs (cyclosporine A), glucocorticoids (dexamethasone, etc.), and by related diseases such as lymphoma, chronic lymphocytic leukemia, and solid tumors. Abnormal increase in immunoglobulin requires consideration of the possibility of hematologic malignancies such as multiple myeloma, Wahl’s macroglobulinemia, systemic amyloidosis, plasma cell leukemia, and other hematologic malignancies. The possibility of IgA nephropathy should also be considered when immunoglobulin A is abnormally elevated. When immunoglobulin abnormality occurs, it is necessary to consult a doctor in time, complete the relevant examination to clarify the specific cause of the disease, and treat the cause of the disease.