Home › Your Bone Health › About Bones About Bones Bone facts Bone health is an important part of general health. Bones are flexible yet strong for movement and protect vital organs. Bones grow in childhood, have a growth spurt in adolescence and are constantly rebuilt during adulthood in a process called ‘remodelling’. Bone is living tissue with some cells breaking down the bone (osteoclasts) while other cells (osteoblasts) rebuild new bone, this is why bones can heal after a break. There are 206 bones in the body – the smallest bone is in our ear and the largest in our leg. A close up image inside a healthy bone below reveals a dense matrix style structure. What is osteoporosis? When the structure of bone is compromised and becomes weaker and less dense the bone has an increased risk of breaking. This is osteoporosis. Any bone can be affected by osteoporosis. However osteoporosis tends to affect particular sites within the skeleton, not the whole skeleton. Research has shown the common sites where broken bones occur are the hip, wrist and spine. Other sites include the ankle, leg, forearm, upper arm and ribs. These fractures typically occur after a minor trip, fall or similar incident. Broken bones can occur in patients with either osteoporosis or osteopenia (low bone density). Once a fracture occurs the person is considered to be at much higher risk of another fracture. The aim of early diagnosis and treatment for osteoporosis (and managing osteopenia) is to prevent any initial fracture occurring. If a fracture does occur the main aim of treatment is to reduce the likelihood of more fractures. How common is osteoporosis? Over 1 million Australians have osteoporosis. In those aged 50 years and over 66% have osteoporosis or osteopenia. There are over 173,000 broken bones each year due to poor bone health. What causes poor bone health? Research has identified common risk factors for developing osteoporosis. Your doctor should investigate these risk factors. This mainly applies to patients 50 years and over but can also apply to younger adults. A bone density scan is the most common test to help diagnose osteoporosis. Tips for maintaining bone health Maintaining healthy bones requires adequate levels of calcium, vitamin D and exercise. Protein is also essential for muscle development and strength to support staying active. Some micronutrients also play a lesser role in bone health.