Multiple myeloma is a malignant tumor in which plasma cells proliferate abnormally. MM has a wide range of clinical manifestations, including anemia, infection, bleeding, bone pain, renal insufficiency, neurological symptoms, hypercalcemia, amyloidosis, etc. I. Symptoms caused by secretion of large amount of M protein by multiple myeloma cells 1. Hyperviscosity syndrome of multiple myeloma: about 2%-5% incidence, dizziness, blurred vision, visual impairment, and sudden syncope and impaired consciousness. 2.Secondary infection of multiple myeloma: Infection is mostly seen in bacteria, but also in fungi and viruses, most commonly bacterial pneumonia, urinary tract infection, sepsis, and viral herpes zoster are also seen. 3.amyloidosis of multiple myeloma: the incidence is 5%-10%, often occurring in the tongue, skin, heart, gastrointestinal tract and other parts. 4. Renal impairment of multiple myeloma: 50%-70% of patients have protein, red blood cells, white blood cells and tubular type in urine test, chronic renal failure, hyperphosphatemia, hypercalcemia and hyperuricemia, and uric acid stones may be formed. Second, multiple myeloma tumor cell infiltration manifestation 1, liver, spleen, lymph nodes and kidney infiltration liver, spleen mild or moderate enlargement, neck lymph node enlargement, myeloma kidney. 2. Bone pain, bone deformation and pathological fracture Myeloma cells activate osteoclasts by secreting osteoclastic activity factor, which causes bone lysis and destruction. Bone pain is the most common symptom appearing early, accounting for about 70%, mostly in lumbosacral, sternum and ribs. Due to the destruction of bone by tumor cells, pathological fracture is caused, and multiple fractures can exist at the same time. 3.Anemia and bleedingAnemia is more common and is the first symptom, early anemia is light, late anemia is serious. Thrombocytopenia, bleeding symptoms are more common, skin and mucous membrane bleeding is more common, serious internal organs and intracranial bleeding can be seen. 4, other symptoms some patients in the early or late stage can appear limb paralysis, diplopia, blindness, drowsiness, coma, vision loss.