Fracture Liaison Service
Osteoporosis and Your Bones
Bones Are Continually Changing
Your bones are not like the dry white bones you see in skeletons at Halloween. Bones are made up of living tissue; every cell in your bones is alive, and they are continually changing. Old dead cells are carried away and replaced by new healthy cells. The cells that carry old bone away are called osteoclasts. The cells that replace old bone with new are called osteoblasts.
How Aging Affects Change
When you were a child, your bones grew rapidly. In fact, children only need about two years to completely replace their bone cells. Bones continue to grow in density through your late 20s. At that time, the amount of old cells removed and new healthy cells replacing them were about the same. This keeps a healthy “bone bank account.”
In your mid-30s, however, the removal and replacement of cells can begin to get out of balance. Unlike children, the adult body can take seven to 10 years to replace all the bone cells. As you continue to age, your body becomes less capable of replacing the cells that were lost, and thus the bones become thinner. Bone loss is normal, and not everyone will develop osteoporosis. If you have osteoporosis, you have a negative bone balance in your bone bank account.
Did You Know?
The interior of your bones are made up of bone fibers that crisscross each other in layers. The fibers are precisely aligned to carry the forces of tension and compression. This allows your bones to be both lightweight and strong.