A condition in which the bones become so porous and weak that they are likely to break from a minor injury. A person with osteoporosis can break a bone from a minor fall, picking up a bag of groceries, and in more serious cases, from a simple action such as a sneeze. While the most common osteoporosis fractures occur in the hip, vertebrae (bones in the spine) and wrist, these fractures also occur in many other bones.