Three diseases of bone are common in the elderly: osteoporosis, osteomalacia and Paget’s disease of bone. Osteoporosis is the result of bone loss, caused by a change in factors that regulate bone cell metabolism. The process of bone loss itself, resulting in osteoporosis, does not cause symptoms. It is the consequences of osteoporosis, fractures and bone deformity, that patients complain of. Osteomalacia is a defect in the process of mineralization of bone, nearly always due to vitamin D deficiency. In contrast to osteoporosis, patients with osteomalacia may have complaints of bone pain and muscle weakness. Page’s disease of bone is probably caused by a slow virus, which initially affects osteoclasts, followed by stimulation of osteoblasts. The process of increased bone cell turnover itself does not usually cause complaints. However, it results in deformation of bones and joints causing a painful secondary osteoarthritis. Pain resulting from high bone cell turnover responds remarkably quickly to treatment. In exceptional cases local pain in the long bones occurs. In an earlier review the problems of origin, diagnosis and treatment of osteoporosis were discussed. This paper focuses on diagnostic procedures and therapeutic regimens.