Advanced stage of multiple myeloma is commonly seen in DS stage III. Symptoms include hypercalcemia, multiple skeletal lesions, and renal damage. 1. Hypercalcemia: extensive osteolytic disease can lead to elevated blood calcium and urinary calcium, which manifests as anorexia, nausea, polyuria, thirst, irritability, cardiac arrhythmia, and fainting in severe cases. 2. Multiple bone lesions: bone marrow tumor cells invade and produce osteoclast activating factor, which can cause osteolytic injury. 2/3 of the patients mainly suffer from bone pain, which is mostly seen in the chest and lumbar back, and aggravated with movement. The diseased bone can be bulged locally with certain elasticity and rattling sound, and it is easy to have pathologic fracture, causing compression of nerve root or spinal cord. 3. Renal damage: there is a large amount of deposition of monoimmunoglobulin in the renal tubules, as well as hyperviscosity, amyloidosis, myeloma cell infiltration, pyelonephritis and so on. All of the above advanced lesions can lead to the death of patients with multiple myeloma, and standardized treatment is recommended to prolong the survival period.