Bone pain in both arms and legs may be caused by the following reasons: 1. It is caused by osteoporosis, often seen in elderly patients or patients with severe malnutrition. Once such patients develop, they often have bony pain in multiple places throughout the body, and the extremities are common sites of onset. 2. It may be caused by infection involving the whole body, due to severe systemic infection, resulting in multiple Osteomyelitis, there will be bony pain in the extremities. If there are multiple bone or joint tuberculosis lesions throughout the body, this kind of bony pain in the extremities may also occur. 3. It may also be caused by multiple bony tumors, and bony pain may occur when patients have metastases involving the bones of the extremities. 4. It may also be caused by multiple injuries to the extremities, such as patients who have suffered multiple traumas in a car accident, which may cause bony pain in the extremities.