The abnormal increase of IgM in the blood is macroglobulinemia. This disease is divided into primary and secondary. The cause of primary macroglobulinemia is unknown, and it is also called Waldenstrom's macroglobulinemia. This disease can be divided into primary and secondary. The increase of monoclonal IgM for unknown reasons is called primary macroglobulinemia (Waldenstrom macroglobulinemia), and the increase of monoclonal or polyclonal IgM secondary to other diseases is called secondary macroglobulinemia. The clinical manifestations of primary macroglobulinemia are characterized by elderly onset, anemia, bleeding tendency and hyperviscosity syndrome. The diagnosis is based on the appearance of a large number of monoclonal IgM in the blood and lymphoplasmacytic infiltration in the bone marrow. This disease is a chronic process. Chemotherapy is not suitable when there are no clinical symptoms. Chemotherapy is used for progressive diseases.