Osteoporosis is primarily caused by menopause and ageing. However, secondary causes of bone loss can be found in up to 64 percent of patients with osteoporosis. Common medical causes identified have included Vitamin D deficiency, glucocorticoid excess, hyperthyroidism, hyperparathyroidism, malabsorption, hypercalciuria, rheumatoid arthritis, and myeloma, while other lifestyle related causes, such as smoking and excessive alcohol consumption can also result in bone loss. Addressing all of these factors are required to optimise the management of osteoporosis.