The bones in our skeleton are made of a thick outer shell and a strong inner mesh filled with collagen (protein), calcium salts and other minerals. The inside looks like honeycomb, with blood vessels and bone marrow in the spaces between bone.

Osteoporosis occurs when the holes between bone become bigger, making it fragile and liable to break easily. Osteoporosis usually affects the whole skeleton but it most commonly causes breaks (fractures) to bone in the wrist, spine and hip.

Bone is alive and constantly changing. Old, worn out bone is broken down by cells called osteoclasts and replaced by bone building cells, called osteoblasts. This process of renewal is called bone turnover.

Because you cannot see of feel your bone getting thinner you will probably be quite unaware of any problems with your bone health. Osteoporosis is a silent disease and for most people, the first sign that something is wrong can be when they break a bone, often in the wrist or spine after a minor incident, although not all fractures are due to osteoporosis.

A normal x-ray of bone cannot reliably measure bone density, but a bone density scan, called a dual energy x-ray absorptiometry (DXA) scan, is used to measure the density of bones and compare this to a normal range. This test is currently the most accurate and reliable means of assessing the strength of your bones and your risk or fracture.

Everybody as they get older are at risk of getting osteoporosis, but other factors can increase someone's chances, such as :

Early hysterectomy (before the age of 45), particularly when both ovaries are removed (oophorectomy)

A lack of oestrogen, caused by early menopause (before age 45)

Heavy smoking, drinking and other medical disorders can also increase the risk.

You should always discuss your fears, chances and treatment of osteoporosis with your doctor who will advise you on how to prevent the disease.