As we age our bones naturally become thinner as calcium and other minerals are lost causing the bones to become lighter, less dense, and more porous (osteopenia). This makes the bones weaker, and increases the risk of a fracture. With further bone loss, osteopenia leads to osteoporosis a disease in which bones become fragile and more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly and silently until a bone breaks. Any bone can be affected, but typically fractures occur in the hip, spine, and wrist. A hip fracture almost always requires hospitalization and major surgery and can impair a person's ability to walk unassisted and may cause prolonged or permanent disability. Spinal or vertebral fractures also have serious consequences, including loss of height, severe back pain, and deformity. Although osteoporosis can occur in men, it is most common in women older than age 65.