Multiple myeloma (MM) is a malignant neoplasm of abnormal plasma cell proliferation. Multiple myeloma is often associated with multiple osteolytic damage, hypercalcemia, anemia, kidney damage, increased susceptibility to bacterial infections, and suppressed production of normal immunoglobulins. So, what are the complications of multiple myeloma? The following are the complications of multiple myeloma. Kidney damage: It is a common and important complication of MM, and one of the main causes of death of patients. 2.Fracture: pathological fracture, commonly in the skull, pelvis, ribs, spine bone fracture, etc. Hypercalcemia: The incidence of myeloma combined with hypercalcemia can reach 30% to 60% in European and American patients, which can manifest clinically as loss of appetite, nausea, vomiting, irritable polyuria and coma. Acute and chronic renal failure is one of the important complications of multiple myeloma and an important diagnostic clue, which can occur at any stage of multiple myeloma: 1. Hematologic complications: anemia, hemorrhage, and thrombosis. 2. Infection: Infection and fever may recur during the course of the disease. For example, skin infection, lung infection, etc. 3, hyperviscosity syndrome: the incidence is 10% in MM patients, often showing decreased vision, impaired consciousness, central nervous system disorders, heart failure, etc. 4, neurological damage: MM combined with the incidence of neurological damage 28.6% to 40%, including spinal cord compression, nerve root spinal cord compression, etc. 5, amyloidosis: cause the corresponding clinical manifestations, including tongue hypertrophy, parotid enlargement, cardiac hypertrophy, heart enlargement, diarrhea, peripheral neuropathy, hepatosplenomegaly, etc.