Loss of bone tissue, resulting in bones that are brittle and susceptible to fracture

  • Common over the age of 50
  • More common in females
  • Sometimes runs in families; more common in white and Asian people
  • Poor diet, lack of exercise, smoking, and alcohol are risk factors

As people get older, their bones become thinner and lighter. By the age of 70, most people’s skeletons are about a third lighter than they were at the age of 40. This loss of bone density, known as osteoporosis, is the result of an imbalance between the natural breakdown and replacement of bone. Eventually, all elderly people are affected by osteoporosis, but the severity of the condition varies from person to person. People who are thin, who do little exercise, and whose relatives have osteoporosis are likely to develop the condition to a greater degree than others.

Many people do not realize that they have osteoporosis until they fracture a wrist or hip as a result of a minor fall. In the UK, thousands of fractures occur each year in people aged 65 or over. Osteoporosis is a major cause of these fractures, the hip being the most common site. In elderly people, hip fractures are often life-threatening or result in immobility.

What are the causes?

Sex hormones are necessary for bone replacement. In both men and women, osteoporosis begins to develop as sex hormone production declines with age. Any condition that causes this decline to accelerate can increase the severity of age-related osteoporosis. In women, production of the sex hormone oestrogen declines rapidly at the menopause. Early menopause, which tends to occur in women who smoke, increases the risk of osteoporosis. In men, untreated hypogonadism results in low levels of the sex hormone testosterone early in life and a low bone density.

Osteoporosis may occur as a result of long-term treatment with oral corticosteroids. People with rheumatoid arthritis, an overactive thyroid gland (see Hyperthyroidism), or chronic kidney failure are also at increased risk of osteoporosis.

Exercise is essential to maintain bone health. The density of bones declines rapidly in people who are confined to bed and in those whose daily activity is reduced by disorders such as arthritis or multiple sclerosis.

Osteoporosis sometimes runs in families. Women who have a close relative with osteoporosis are more likely to develop the disorder themselves. White and Asian women, especially those who have a slight build, are at increased risk of developing the condition.

Can it be prevented?

Measures to prevent osteoporosis are most effective if they are started early in life. Teenagers and young adults should eat a balanced diet rich in calcium and vitamin D (see A healthy diet) and maintain it throughout life. Calcium is essential for bone strength, and vitamin D aids calcium absorption in the body. Extra calcium is needed during pregnancy, while breast-feeding, and during and after the menopause; it may be advisable to take a supplement at such times (see Vitamin and mineral supplements). Vitamin D is mainly produced in the skin in response to sunlight. People who are exposed to little sunlight may need to take vitamin D supplements.

Walking and other weight-bearing exercise help to increase bone density. Not smoking and limiting the intake of alcohol also reduce the risk of developing osteoporosis.

Anyone thought to be at increased risk of osteoporosis, such as having a family history of the disorder, can have his or her bone density measured (see Bone densitometry). Bone density testing is often used to assess a person’s likelihood of having bone loss and also to monitor people who are taking preventive treatment.

What are the symptoms?

Some physical changes associated with aging are in fact due to osteoporosis. These include:

  • Gradual loss of height.

  • Rounding of the back.

For many people, the first evidence of osteoporosis is a painful fracture of a bone after minor stress or injury. An example is sudden, severe back pain due to a compression fracture of the body of a vertebra (bone of the spine). In severe osteoporosis, a fracture may occur spontaneously.

What might be done?

The diagnosis of osteoporosis is made from your medical history, a physical examination, and bone densitometry. Blood tests are also commonly carried out to look for conditions that can cause osteoporosis, such as hyperthyroidism.

If you have back pain due to a fracture, your doctor may recommend that you take painkillers or use a heat pad on the affected area. Underlying disorders will be treated if possible. For example, you may be prescribed drugs to treat an overactive thyroid gland (see Drugs for hyperthyroidism).

To slow the progression of osteoporosis it is important to follow the advice given here for taking preventive measures. In addition, your doctor may prescribe calcium and vitamin D supplements, and bisphosphonate drugs (see Drugs for bone disorders) to help prevent bone loss and reduce the risk of fractures. If bisphosphonates are not suitable, your doctor may prescribe alternative medications, such as strontium ranalate, calcitonin, or raloxifene. In certain severe cases, parathyroid hormone or a drug called teriparatide may be prescribed. Hormone replacement therapy (HRT) is no longer generally recommended as a first-line treatment for osteoporosis but it may be considered for postmenopausal women when other treatments have been ineffective or are unsuitable. Women who have gone through a premature menopause (before the age of 45) may be advised to have HRT until the age of 50 to protect against their higher risk of osteoporosis. However, even if these measures are taken, some bone loss is inevitable in later life.

Spine affected by osteoporosis

This colour-enhanced X-ray shows severe curvature of the upper spine due to compression fractures of vertebrae that have been weakened by osteoporosis.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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