Bone pain is the most frequent symptom in patients with osseous metastases. More than 50% of these patients experience bone pain before or at the time of diagnosis of skeletal metastases. The pain is constantly present and may increase in intensity. Multiple myeloma and osteomyelosclerosis are also often accompanied by severe bone pain. Bone pain has a complex aetiology, incompletely understood. Mechanical factors include increased pressure in the bone marrow, bending or distortion of the bone, stretching of the periosteum and/or endosteum and destruction of the bone.