Osteoporosis is a disease in which bones become fragile and more likely to fracture. Usually the bone loses density, which measures the amount of calcium and minerals in the bone.
Thin bones; Low bone density
Causes, incidence, and risk factors
Osteoporosis is the most common type of bone disease.
About half of all women over the age of 50 will have a fracture of the hip, wrist, or vertebra (bone of the spine) during their lifetime.
Bone is living tissue. Existing bone is constantly being replaced by new bone. Osteoporosis occurs when the body fails to form enough new bone, when too much existing bone is reabsorbed by the body, or both.
Calcium is one of the important minerals needed for bones to form. If you do not get enough calcium and vitamin D, or your body does not absorb enough calcium from your diet, your bones may become brittle and more likely to fracture.
Sometimes bone loss occurs without any cause. White women are more likely to have bone loss. Sometimes the tendency to have bone loss and thin bones is passed down through families.
A drop in estrogen in women at the time of menopause and a drop in testosterone in men is a leading cause of bone loss. Other causes of bone loss include:
Being confined to a bed
Certain medical conditions
Taking certain medications
Other risk factors include:
Absence of menstrual periods (amenorrhea) for long periods of time
A family history of osteoporosis
Drinking a large amount of alcohol
Low body weight
There are no symptoms in the early stages of osteoporosis. Many times, people will have a fracture before learning that they have the disease.
Pain almost anywhere in the spine can be caused by fractures of the bones of the spine. These are called compression fractures. They often occur without an injury. The pain may occur suddenly or slowly over time.
There may be a loss of height (as much as 6 inches) over time. A stooped posture or kyphosis (also called a "dowager's hump") may develop.
Medications to treat osteoporosis can help prevent future fractures, but spine bones that have already collapsed cannot be reversed.
Some people with osteoporosis become disabled from weakened bones. Hip fractures are one of the main reasons people are admitted to nursing homes.
Calcium is essential for building and maintaining healthy bone. Vitamin D is also needed because it helps your body absorb calcium. Following a healthy, well-balanced diet can help you get these and other important nutrients throughout life.
Other tips for prevention:
Avoid drinking excess alcohol
Get regular exercise
A number of medications are approved for the prevention of osteoporosis.
Management of osteoporosis in postmenopausal women: 2010 position statement of The North American Menopause Society. Menopause. 2010 Jan-Feb;17(1):25-54.
Lewiecki EM. In the clinic. Osteoporosis. Ann Intern Med. 2011;155(1):ITC1-1-15;quiz ITC1-16.
Park-Wyllie LY, Mamdani MM, Juurlink DN, Hawker GA, Gunraj N, Austin PC, et al. Bisphosphonate use and the risk of subtrochanteric or femoral shaft fractures in older women. JAMA. 2011;305(8):783-789.
National Osteoporosis Foundation. Clinician's Guide to Prevention and Treatment of Osteoporosis. Washington, DC: National Osteoporosis Foundation; 2010.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.