Multiple myeloma is mostly seen in elderly people over 50 years old, and is a common and frequent disease in hematology, but many friends and even many medical personnel are far from knowing enough about it. Because of the complex and diverse clinical manifestations of multiple myeloma and its non-specificity, it is especially easy to miss and misdiagnose, thus delaying treatment. In order to improve the understanding of this disease and reduce misdiagnosis, the causes of misdiagnosis are summarized as follows: 1. Bone pain is the first and prominent clinical manifestation in most patients with multiple myeloma, because myeloma cells secrete cytokines to activate osteoclasts, causing osteoporosis and osteolytic lesions. Bone pain is commonly found in the lumbosacral and thoracic back, early associated with myeloma cell infiltration and osteoporosis, is not severe, can be spontaneously and temporarily relieved, and is most easily misdiagnosed as orthopedic diseases such as disc herniation. 2, multiple myeloma due to a large number of immunoglobulin light chains filtered from the glomerulus and deposited in the renal tubules, causing epithelial cell degeneration and necrosis, together with hypercalcemia, hyperviscosemia, amyloidosis and infiltration of myeloma cells into the kidney, renal damage and renal dysfunction are often the main complications and early manifestations of multiple myeloma. Patients often have varying degrees of proteinuria, and about half of them may develop renal insufficiency and be misdiagnosed as kidney disease. 3. Because of the malignant proliferation and infiltration of myeloma cells crowding out normal hematopoietic tissues, affecting hematopoietic function as well as renal function, most of them are combined with different degrees of anemia, and the early manifestations are pallor, weakness, poor performance, dizziness and other anemic symptoms, which are often misdiagnosed as anemia. This can lead to misdiagnosis as various bleeding disorders. Due to the decrease of polyclonal immunoglobulins, B and T lymphatic development defects leading to immunodeficiency and neutrophil reduction, patients are prone to repeated infections, especially pneumonia and respiratory and urinary system diseases in the elderly and misdiagnosed. 5.Much combined with hyperviscosity, leading to microcirculatory disorders, anemia and infiltration of tumor cells, especially amyloidosis caused by the deposition of large amounts of light chains secreted by tumor cells in the myocardium or central nervous system, which is often misdiagnosed as cardiovascular disease. Therefore, the following conditions should be taken seriously in elderly people: unexplained bone pain or pathological fracture, especially those with bone induration and masses in flat bones; unexplained renal impairment with proteinuria, azotemia, anemia not parallel to the degree of renal failure; unexplained anemia with bone pain; recurrent pulmonary infection or urinary tract infection, ineffective by anti-infection treatment, especially those with combined anemia and increased hematocrit. The patient should be treated with anti-infective therapy.