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Glossary of useful terms

Osteoporosis

Osteoporosis is a disease in which the density and quality of bone are reduced, leading to weakness of the skeleton and increased risk of fracture, particularly of the spine, hip and wrist. Osteoporosis is a global public health problem which currently affects approximately one in three women and one in five men, and is increasing in significance as the population of the world both grows in size and is living longer.

Osteopenia

The term used for bone density that is lower than normal, but not low enough to be diagnosed as osteoporosis.

Osteoblasts

Bone-forming cells that lay down new bone during the formation stage of the bone remodeling process. They fill in cavities and tunnels made by the osteoclasts.

Osteoclasts

Bone-removing cells that dissolve and erode bone during the resorption stage of the bone remodeling process.

Bone remodeling

A lifelong process where old bone is removed from the skeleton and replaced with new bone. There are two stages, resorption and formation, which need to be carefully balanced to maintain bone strength. With menopause, bone resorption is greater than bone formation; the activity of the osteoblasts cannot keep up with the activity of the osteoclasts, and women begin to lose bone more rapidly.

Bone resorption

The first stage of the bone remodeling process in which bone is broken down. Osteoclasts attach to the bone surface and erode it, creating small cavities in bone surface.

Bone formation

The second stage of the bone remodeling process in which new bone is formed. Osteoblasts fill in the cavities and tunnels (created by osteoclasts) with new bone until the bone surface is restored.

Bone mineral density

Bone density is a measure of grams of mineral (calcium) (BMD) per area and is often used as a proxy measure for bone strength (due to the fact there is currently no accurate measure of overall bone strength).

Kyphosis

Commonly known as "dowager's hump", this condition sees a forward curvature of the upper spine caused by fractures of the vertebrae and compression of the spinal column.

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