Mrs. Wang, 65 years old, usually has no health problems, and has been actively involved in morning exercises, hiking and other elderly sports activities. In the past six months, she had pain in her right calf, and the X-ray examination did not reveal anything. After the radioisotope bone scan, many large and small lesions were found in the thoracic spine, lumbar spine and legs, and the culprit was found. Bone pain is one of the symptoms caused by bone metastasis of tumor, which mostly occurs in patients over 40 years old. Sometimes, the primary tumor only has metastatic bone pain as the first symptom and is not accompanied by other symptoms. Any malignant tumor has the possibility of bone metastasis. The cancers with high to low incidence of bone metastasis are: prostate cancer (85%), breast cancer (80%), thyroid cancer (50%), lung cancer (44%) and kidney cancer (30%). It is characterized by intermittent or persistent pain, which is worsening day by day, unbearable, especially at night, sometimes with pressure pain, percussion pain, and even pathological fracture as the first symptom in severe cases. Both the old people themselves and their children will think that it is inevitable for the old people to have back pain when they are old, but it is important to take it seriously when there is persistent bone pain in the back, because 80% of the occurrence of tumor metastatic bone pain is in the spine. It is important to distinguish cancer bone pain from orthopedic related bone pain. Generally, low back pain is commonly caused by acute lumbar sprain, lumbar muscle and sacroiliac joint strain, discogenic low back pain, lumbar transverse synovial syndrome, etc. Most of the causes are trauma, weight bearing, cold and humidity, most of the low back activities are restricted, and the pain is aggravated by sitting or bending for a long time. However, bone pain caused by tumor metastasis cannot be relieved by the above treatments or is still progressively aggravated after a short period of relief, then we should be alert to the occurrence of metastatic cancer pain and go to hospital for consultation and treatment as soon as possible. However, some people have raised the question, why did I not find any abnormal examination even after taking X-ray film? This is because it is more difficult to diagnose metastatic lesions of tumor by early X-ray plain film. Only when the destruction of spine reaches more than 1~1.5 cm and the bone decalcification is 50%~70%, the damage of bone can be observed by X-ray film. If cancer metastatic bone pain is suspected, it is necessary to combine X-ray, radioisotope bone scan (ECT), magnetic resonance imaging (MRI), CT and other examination methods. Isotope bone scan is the initial screening diagnosis of bone metastasis, which is one of the highly sensitive methods to check whether the bone is invaded by cancer, with the advantages of high sensitivity, early detection and whole body imaging not easy to miss, and can detect bone metastasis 6 months earlier than X-ray examination. It can detect bone metastases 6 months earlier than X-ray examination. When metastatic lesions are detected, MRI and CT examination can be performed further. The accuracy of MRI in detecting bone metastases is over 90%, and MRI can observe the tumor invasion of spinal bone, spinal cord, nerves and soft tissues, while CT examination can detect osteolytic, osteogenic and mixed destruction. Due to the high aggressiveness of metastatic tumors, early diagnosis and treatment is the best way to avoid cancer deterioration, so as not to delay the disease due to carelessness. In addition, even if elderly people have cancer, as long as they treat it correctly, build up confidence and cooperate with doctors for regular and systematic treatment, they can also prolong their life and improve their quality of life.