Osteoporosis. Artwork depicting a woman with a bent back superimposed over her spine and a close up of her spinal tissue showing the presence of osteoporosis, or brittle bone" disease. The woman has kyphosis, excessive backward curvature of the spine, due to her weakened bones. Osteoporosis is revealed by the cancellous, or spongy appearance of the bone tissue (at left and right). Such bone has a reduced density, is more brittle and prone to fracture. Osteoporosis more commonly affects women due to the reduction in the production of oestrogen, a hormone, by the ovaries at the menopause. Hormone replacement therapy is used to stop further bone loss."