A broken bone is known as a fracture. This can be a crack, buckle or crumple in the structure of the bone, or a complete break, producing two or more fragments. Bone has tough structure and is normally able to tolerate strong forces, but bones can be fractured if they suffer direct impact or if they are exposed to strong twisting or bending. This can happen as a result of a fall or collision. Bone also has a blood and nerve supply. This explains why fractured bones are painful, and result in bleeding and subsequent bruising.
Elderly people are at increased risk of fractures because they tend to be more prone to falls and have reduced bone strength. Children are also more likely to have falls and accidents, which can result in a fracture, partly because they are less aware of hazards.