Caption

Osteoporosis of the back, coloured X-ray. Osteoporosis is a condition in which bone density is reduced, weakening the bones and making them susceptible to fractures. Weakening of the vertebrae (blocks), the bones that make up the spine, can cause them to collapse (compression fractures), which leads to pronounced forward curvature of the spine (the front of the body is at left). This causes back pain, a reduction in height and reduced mobility. Osteoporosis is most common in women after the menopause, as the ovaries stop producing oestrogen hormones, which help to maintain bone mass. Treatment is with drugs that inhibit bone resorption, vitamin D and calcium supplements, drugs that target oestrogen receptors, or hormone replacement therapy.