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The word osteoporosis literally means "porous bones." It occurs when bones lose an excessive amount of their protein and mineral content, particularly calcium. Over time, bone mass, and therefore bone strength, is decreased. As a result, bones become fragile and break easily. Even a sneeze or a sudden movement may be enough to break a bone in someone with severe osteoporosis.


Osteoporosis is a serious public health problem. Some 44 million people in the United States are at risk for this potentially debilitating disease, which is responsible for 1.5 million fractures (broken bones) annually. These fractures, which are often the first sign of the disease, can affect any bone, but the most common locations are the hip, spine, and wrist. Breaks in the hip and spine are of special concern because they almost always require hospitalization and major surgery, and may lead to other serious consequences, including permanent disability and even death.
To understand osteoporosis, it is helpful to understand the basics of bone formation. Bone is living tissue that is constantly being renewed in a two-stage process (resorption and formation) that occurs throughout life. In the resorption stage, old bone is broken down and removed by cells called osteoclasts. In the formation stage, cells called osteoblasts build new bone to replace the old. During childhood and early adulthood, more bone is produced than removed, reaching its maximum mass and strength by the mid-30s. After that, bone is lost at a faster pace than it is formed, so the amount of bone in the skeleton begins to slowly decline. Most cases of osteoporosis occur as an acceleration of this normal aging process, which is referred to as primary osteoporosis. The condition also can be caused by other disease processes or prolonged use of certain medications that result in bone loss. If so, this is called secondary osteoporosis.
Osteoporosis occurs most often in older people and in women after menopause. It affects nearly half of men and women over the age of 75. Women are about five times more likely than men to develop the disease. They have smaller, thinner bones than men to begin with, and they lose bone mass more rapidly after menopause (usually around age 50), when they stop producing a bone-protecting hormone called estrogen. In the five to seven years following menopause, women can lose about 20% of their bone mass. By age 65 or 70, though, men and women lose bone mass at the same rate. As an increasing number of men reach an older age, there is more awareness that osteoporosis is an important health issue for them as well. In fact, a 2003 report noted that one in every eight men over age 50 will suffer a hip fracture as a result of osteoporosis.

Causes and symptoms

A number of factors increase the risk of developing osteoporosis. They include:
  • Age. Osteoporosis is more likely as people grow older and their bones lose tissue.
  • Gender. Women are smaller and start out with less bone. They also lose bone tissue more rapidly as they age. While women commonly lose 30-50% of their bone mass over their lifetimes, men lose only 20-33%.
  • Race. Caucasian and Asian women are most at risk for the disease, but African American and Hispanic women can get it too.
  • Figure type. Women with small bones and those who are thin are more liable to have osteoporosis.
  • Early menopause. Women who stop menstruating early because of heredity, surgery or lots of physical exercise may lose large amounts of bone tissue early in life. Conditions such as anorexia and bulimia also may lead to early menopause and osteoporosis.
  • Lifestyle. People who smoke or drink too much, or do not get enough exercise have an increased chance of osteoporosis.
  • Diet. Those who do not get enough calcium or protein may be more likely to have osteoporosis. That is why people who constantly diet are more prone to the disease.
  • Genetics. Research in Europe reported in 2003 that variations of a gene on chromosome 20 might make some postmenopausal women more likely to have osteoporosis. Studies were continuing on how to identify the gene and use information from the research to prevent osteoporosis in carriers.
Osteoporosis is often called the "silent" disease, because bone loss occurs without symptoms. People often do not know they have the disease until a bone breaks, frequently in a minor fall that would not normally cause a fracture. A common occurrence is compression fractures of the spine. These can happen even after a seemingly normal activity, such as bending or twisting to pick up a light object. The fractures can cause severe back pain, but sometimes go unnoticed—either way, the vertebrae collapse down on themselves, and the person actually loses height. The hunchback appearance of many elderly women, sometimes called "dowager's" hump or "widow's" hump, is due to this effect of osteoporosis on the vertebrae.


Certain types of doctors may have more training and experience than others in diagnosing and treating people with osteoporosis. These include a geriatrician, who specializes in treating the aged; an endocrinologist, who specializes in treating diseases of the body's endocrine system (glands and hormones); and an orthopedic surgeon, who treats fractures such as those caused by osteoporosis.
Before making a diagnosis of osteoporosis, the doctor usually takes a complete medical history, conducts a physical exam, and orders x rays, as well as blood and urine tests, to rule out other diseases that cause loss of bone mass. The doctor also may recommend a bone density test. This is the only way to know for certain if osteoporosis is present. It also can show how far the disease has progressed.
Several diagnostic tools are available to measure bone density. The ordinary x ray is one, though it is the least accurate for early detection of osteoporosis, because it does not reveal bone loss until the disease is advanced and most of the damage has already been done. Two other tools that are more likely to catch osteoporosis at an early stage are computed tomography scans (CT scans) and machines called densitometers, which are designed specifically to measure bone density.
The CT scan, which takes a large number of x rays of the same spot from different angles, is an accurate test, but uses higher levels of radiation than other methods. The most accurate and advanced of the densitometers uses a technique called DEXA (dual energy x-ray absorptiometry). With the DEXA scan, a double x-ray beam takes pictures of the spine, hip, or entire body. It takes about 20 minutes to do, is painless, and exposes the patient to only a small amount of radiation—about one-fiftieth that of a chest x ray.
Doctors do not routinely recommend the test, partly because access to densitometers is still not widely available. People should talk to their doctors about their risk factors for osteoporosis and if, and when, they should get the test. Ideally, women should have bone density measured at menopause, and periodically afterward, depending on the condition of their bones. Men should be tested around age 65. Men and women with additional risk factors, such as those who take certain medications, may need to be tested earlier.


There are a number of good treatments for primary osteoporosis, most of them medications. Two medications, alendronate and calcitonin (in nose spray form), have been approved by the Food and Drug Administration (FDA). They provide people who have osteoporosis with a variety of choices for treatment. For people with secondary osteoporosis, treatment may focus on curing the underlying disease.


For many women who have gone through menopause, the treatment of choice for osteoporosis has been hormone replacement therapy (HRT), also called estrogen replacement therapy. Many women choose HRT when they undergo menopause to alleviate symptoms such as hot flashes, but hormones increase a woman's supply of estrogen, which helps build new bone, while preventing further bone loss. A 2002 report from a large clinical trial called the Women's Health Initiative helped verify HRT's positive effects in preventing osteoporosis in postmenopausal women.
However, the WHI also revealed several risks with taking combined HRT (estrogen and progesterone). In fact, the trial was stopped early because the incidence of invasive breast cancer in women on HRT passed a threshold that was considered too risky for the benefits they were receiving. The study also found that the women on combined hormone therapy were at increased risk for coronary heart disease and stroke. Whether or not a woman takes hormones and for how long is a decision she should make carefully with her doctor. Women should talk to their doctors about personal risks for osteoporosis, as well as their risks for heart disease and breast cancer.
Since estrogen may no longer be recommended for prevention of osteoporosis, selective use of alendronate and calcitonin are possible alternatives. Alendronate and calcitonin both stop bone loss, help build bone, and decrease fracture risk by as much as 50%. Alendronate (sold under the name Fosamax) is the first nonhormonal medication for osteoporosis ever approved by the FDA. It attaches itself to bone that has been targeted by bone-eating osteoclasts, protecting the bone from these cells. Osteoclasts help the body break down old bone tissue.
Calcitonin is a hormone that has been used as an injection for many years. A new version is on the market as a nasal spray. It too slows down bone-eating osteoclasts.
Side effects of these drugs are minimal, but calcitonin builds bone by only 1.5% a year, which may not be enough for some women to recover the bone they lose. Fosamax has proven safe in large, multi-year studies, but not much is known about the effects of its long-term use. Several medications under study include other bisphosphonates that slow bone breakdown (like alendronate), sodium fluoride, vitamin D metabolites, and selective estrogen receptor modulators. Some of these treatments are already being used in other countries, but have not yet been approved by the FDA for use in the United States.
In early 2003, a report announced that the FDA had recently approved the first drug that could form bone in osteoporosis patients. The drug is a form of the human parathyroid hormone called teriparatide. It shows promise for those patients at highest risk for fracture from the disease. There are some patients who cannot use the drug, so all considering the new treatment must check with their physician and may need to undergo bone densitometry scans or other testing.


Unfortunately, much of the treatment for osteoporosis is for fractures that result from advanced stages of the disease. For complicated fractures, such as broken hips, hospitalization and a surgical procedure are required. In hip replacement surgery, the broken hip is removed and replaced with a new hip made of plastic, or metal and plastic. Though the surgery itself is usually successful, complications of the hip fracture can be serious. Those individuals have a 5-20% greater risk of dying within the first year following the injury than do others in their age group. A large percentage of those who survive are unable to return to their previous level of activity, and many move self-care to a supervised living situation or nursing home. That is why getting early treatment and taking steps to reduce bone loss are vital.

Alternative treatment

Alternative treatments for osteoporosis focus on maintaining or building strong bones. A healthy diet low in fats and animal products and containing whole grains, fresh fruits and vegetables, and calcium-rich foods (such as dairy products, dark-green leafy vegetables, sardines, salmon, and almonds), along with nutritional supplements (such as calcium, magnesium, and vitamin D), and weight-bearing exercises are important components of both conventional prevention and treatment strategies and alternative approaches to the disease. In addition, alternative practitioners recommend a variety of botanical medicines or herbal supplements. Herbal supplements designed to help slow bone loss emphasize the use of calcium-containing plants, such as horsetail (Equisetum arvense), oat straw (Avena sativa), alfalfa (Medicago sativa), licorice (Glycyrrhiza galbra), marsh mallow (Althaea officinalis), and yellow dock (Rumex crispus). Homeopathic remedies focus on treatments believed to help the body absorb calcium. These remedies are likely to include such substances as Calcarea carbonica (calcium carbonate) or silica. In traditional Chinese medicine, practitioners recommend herbs thought to slow or prevent bone loss, including dong quai (Angelica sinensis) and Asian ginseng (Panax ginseng). Natural hormone therapy, using plant estrogens (from soybeans) or progesterone (from wild yams), may be recommended for women who cannot or choose not to take synthetic hormones.


There is no cure for osteoporosis, but it can be controlled. Most people who have osteoporosis fare well once they receive treatment. The medicines available now build bone, protect against bone loss, and halt the progress of this disease.


Building strong bones, especially before the age of 35, and maintaining a healthy lifestyle are the best ways to prevent osteoporosis. To build as much bone mass as early as possible in life, and to help slow the rate of bone loss later in life, doctors advise:

Getting calcium from foods

Experts recommend 1,500 milligrams (mg) of calcium per day for adolescents, pregnant or breastfeeding women, older adults (over 65), and postmenopausal women not using hormone replacement therapy. All others should get 1,000 mg per day. Foods are the best source for this important mineral. Milk, cheese, and yogurt have the highest amounts. Other foods that are high in calcium are green leafy vegetables, tofu, shellfish, Brazil nuts, sardines, and almonds.

Taking calcium supplements

Many people, especially those who do not like or can not eat dairy foods, do not get enough calcium in their diets and may need calcium supplements. Supplements vary in the amount of calcium they contain. Those with calcium carbonate have the most amount of useful calcium. Supplements should be taken with meals and accompanied by six to eight glasses of water a day.

Getting vitamin d

Vitamin D helps the body absorb calcium. People can get vitamin D from sunshine with a quick (15-20 minute) walk each day or from foods such as liver, fish oil, and vitamin-D fortified milk. During the winter months it may be necessary to take supplements. Four hundred mg daily is usually the recommended amount.

Avoiding smoking and alcohol

Smoking reduces bone mass, as does heavy drinking. Avoiding smoking and limiting alcoholic drinks to no more than two per day reduces risks. An alcoholic drink is one-and-a-half ounces of hard liquor, 12 ounces of beer, or five ounces of wine.


Exercising regularly builds and strengthens bones. Weight-bearing exercises—where bones and muscles work against gravity—are best. These include aerobics, dancing, jogging, stair climbing, tennis, walking, and lifting weights. People who have osteoporosis may want to attempt gentle exercise, such as walking, rather than jogging or fast-paced aerobics, which increase the chance of falling. Exercising three to four times per week for 20-30 minutes each time helps.



Doering, Paul L. "Treatment of Menopause Post-WHI: What Now?" Drug Topics April 21, 2003: 85.
Elliott, William T. "HRT, Estrogen, and Postmenopausal Women: Year-old WHI Study Continues to Raise Questions." Critical Care Alert July 2003: 1.
LoBuono, Charlotte. "New Osteoporosis Drug is First to Form Bone." Drug Topics January 6, 2003: 24.
"More Men at Osteoporosis Risk than Commonly Believed." Tufts University Health and Nutrition Letter August 2003: 8.
Nelson, Heidi D. "Postmenopausal Osteoporosis and Estrogen." American Family Physician August 15, 2003: 606.
"Osteoporosis Gene Identified." Diagnostics and Imaging Week March 13, 2003 4.
"Three Out of Four Women Currently Taking Prescriptions for Osteoporosis Are Not Receiving Full Treatment, According to Recent Data from a National Physician Audit." Drug Cost Management Report January 2003: 11.

Key terms

Alendronate — A nonhormonal drug used to treat osteoporosis in postmenopausal women.
Anticonvulsants — Drugs used to control seizures, such as in epilepsy.
Biphosphonates — Compounds (like alendronate) that slow bone loss and increase bone density.
Calcitonin — A hormonal drug used to treat postmenopausal osteoporosis
Estrogen — A female hormone that also keeps bones strong. After menopause, a woman may take hormonal drugs with estrogen to prevent bone loss.
Glucocorticoids — Any of a group of hormones (like cortisone) that influence many body functions and are widely used in medicine, such as for treatment of rheumatoid arthritis inflammation.
Hormone replacement therapy (HRT) — Also called estrogen replacement therapy, this controversial treatment is used to relieve the discomforts of menopause. Estrogen and another female hormone, progesterone, are usually taken together to replace the estrogen no longer made by the body.
Menopause — The ending of a woman's menstrual cycle, when production of bone-protecting estrogen decreases.
Osteoblasts — Cells in the body that build new bone tissue.
Osteoclasts — Cells that break down and remove old bone tissue.
Selective estrogen receptor modulator — A hormonal preparation that offers the beneficial effects of hormone replacement therapy without the increased risk of breast and uterine cancer associated with HRT.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


a decreased mass per unit volume of normally mineralized bone, calculated in comparison to age- and sex-matched controls; it is the most prevalent bone disease worldwide. There are many etiologic factors of osteoporosis, which give the various types their names.

Postmenopausal, estrogen-deficient osteoporosis is the most common type; more than half the women in the United States 50 years of age or older are likely to have radiologically detectable evidence of abnormally decreased bone mass (osteopenia) in the spine, and in more than a third, major orthopedic problems related to osteoporosis will eventually occur. Most fractures sustained by women over the age of 50 are secondary to osteoporosis. Women at risk for this disorder can reduce that risk by maintaining adequate calcium levels with dietary calcium or calcium supplements (see diet-related bone loss below), and taking estrogen in the perimenopausal period when indicated. Estrogen replacement therapy is especially recommended for women whose ovaries were removed before age 50.

Age-related osteoporosis is a type that occurs in both men and women and is caused by bone loss that normally accompanies aging.

Diet-related bone loss is caused by chronic dietary deficiencies in calcium and protein, as well as deficiency in vitamin C, which is an essential cofactor in collagen metabolism. Intestinal absorption of calcium becomes less efficient with age; hence older persons need more rather than less dietary calcium to maintain a positive calcium balance. Although dairy products are the primary source of dietary calcium, supplementary calcium is needed by some women. Healthy premenopausal women over the age of 30 may need as much as 1000 mg of calcium a day, which is the amount supplied by a quart of milk. However, for pregnant women and those over the age of 50, the recommended daily intake increases to more than 1500 mg. Lactating women need 2000 mg of calcium daily to prevent untimely catabolism of bone. The vitamin D metabolite 1,25-dihydroxycholecalciferol is the active hormone that helps maintain normal serum calcium and phosphate levels. Because of inadequate exposure to sunlight, decreased intestinal absorption of vitamin D, and limited intake of milk, elderly persons often are vitamin D–deficient. Vitamin D is a component of multivitamins, and health care providers often recommend supplemental multivitamins for the elderly.

Disuse osteoporosis is related to the response of bone mass change to mechanical stress. Net bone mass does not change throughout much of adult life; however, living bone is never metabolically at rest and constantly remodels and reappropriates its mineral stores along lines of mechanical stress. Without weight-bearing stress, bone mass diminishes. As much as 30 to 40 per cent of initial bone mass may be lost after six months of total immobilization, as in paraplegia and quadriplegia due to spinal cord injury. Movement alone is not sufficient to prevent osteoporosis. There must be weight-bearing activity and the use of antigravity muscles to maintain healthy bones.

Heritable osteoporosis includes at least four types of congenital diseases grouped under the term osteogenesis imperfecta. Symptoms of varying severity that are characteristic of these disorders include skeletal fragility, multiple pathologic fractures, generalized osteoporosis, and scoliosis. All of the diseases included under osteogenesis imperfecta are thought to be associated with defective bone matrix formation.

Endocrine-mediated bone loss can produce osteoporosis because numerous endocrine hormones affect skeletal remodeling and hence skeletal mass. Examples of endocrine disorders that can produce associated osteopenia include hypogonadism, hyperthyroidism, hyperparathyroidism, and hyperadrenalism or chronic glucocorticoid hormone excess.

Disease-related bone loss can occur with almost any kind of chronic disease that is associated with malnutrition and disuse. Osteopenia is also a common complication of most tumors of the bone marrow. Leukemia, lymphoma, and the extremely rare mast cell tumor also may be associated with osteoporosis.

Idiopathic osteoporosis, in both the adult and juvenile form, is extremely uncommon. Drug-induced bone loss may be associated with long-term use of heparin for anticoagulation therapy or with the administration of methotrexate, which has both cytotoxic and calciuric effects.
Diagnosis. Osteoporosis is an insidious disease that silently robs the skeleton of its banked resources. Sometimes it is decades before the bone is weak enough to sustain a spontaneous fracture. The most common sites for such bone loss and consequent fractures are the thoracic and lumbar vertebral bodies, ribs, proximal femur, and distal radius. The earliest signs of osteoporosis are often associated with compression fracture of the spine characterized by an episode of acute pain in the middle to low thoracic or high lumbar region. Prevention of osteoporosis through diet, exercise, and the reduction of risk factors should be a priority. The critical years for building bone mass are before the age of 30. Maintenance of skeletal mass is accomplished by oral calcium supplementation, vitamin D therapy, weight-bearing activity through a daily exercise program, and sodium fluoride therapy.

During the intervals between compression fractures, the patient may be symptom-free, but kyphosis, decrease in height, and appearance of a “dowager's hump” are reliable indicators of the early progress of the disease. Two other associated effects of vertebral compression are the result of a decrease in the size of the thoracic and abdominal cavities. The patient experiences diminished activity tolerance as a result of disease-related postural changes and often reports early satiety and a bloated feeling after eating only a small amount of food.

Radiographs of the thoracic and lumbar spine show a visible loss of bone density. In general, as much as 30 to 50 per cent of the bone mass must be lost before the decrease can be seen on x-ray. Bone density measurement can help in evaluation of this disease and prediction of the likelihood of fracture.
Treatment and Patient Care. The management of osteoporosis is concerned with treatment of symptomatic disease and its sequelae and with maintenance of skeletal mass and integrity. Treatment of acute symptoms is aimed at relieving pain, providing comfortable mechanical support for the spine, arranging assistance in activities of daily living, coordinating a rehabilitation program, and providing encouragement and reassurance to the patient and family. The rehabilitation process must include instruction in proper back care, and especially in how to avoid unnecessary spinal compression forces while lifting or bending.

Estrogen replacement therapy is often prescribed for women at menopause. Because it increases the risk for breast and gynecologic malignancies, careful assessment of these patients is necessary. Pharmacologic agents approved by the Food and Drug Association for osteoporosis treatment or treatment include the bisphosphonatesalendronate and risedronate; calcitonin, estrogen replacement therapy, and selective estrogen receptor modulators such as raloxifene.

Information on osteoporosis can be obtained by writing the National Osteoporosis Foundation, 1232 22nd St. NW, Washington, DC 20037-1292 or consulting their web site at http://www.nof.org. They have also published clinical guidelines for the prevention and treatment of osteoporosis on their web site.
Loss of bone mass due to osteoporosis produces characteristic changes in the curvature of the spine. At far left are normal curvatures compared with those typical of osteoporosis. Figures to the right show the normal spine at age 40 and osteoporotic changes at 60 and 70 years of age. As shown, these changes bring about a loss of as much as 6 to 9 inches in height, and the so-called dowager's hump in the upper thoracic vertebrae.
osteoporosis circumscrip´ta demineralization occurring in localized areas of bone, especially in the skull.
osteoporosis of disuse that occurring when the normal laying down of bone is slowed because of lack of the normal stimulus of functional stress on the bone.
post-traumatic osteoporosis loss of bone substance after an injury in which there is nerve damage, sometimes due to decreased blood supply caused by the neurogenic insult, or to disuse secondary to pain. Called also Sudeck's disease.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


Reduction in the quantity of bone or atrophy of skeletal tissue; an age-related disorder characterized by decreased bone mass and loss of normal skeletal microarchitecture, leading to increased susceptibility to fractures.
[osteo- + G. poros, pore, + -osis, condition]

Osteoporosis affects 20 million U.S. residents, about 80% of them women, and costs U.S. society as much as $13.8 billion annually. About 1.3 million fractures attributable to osteoporosis occur each year in people aged 45 and older, and this condition is responsible for 50% of fractures occurring in women older than age 50. Although all bones are affected, compression fractures of the vertebrae and traumatic fractures of the wrist and femoral neck are most common. Loss of body height and development of kyphosis may be the only signs of vertebral collapse. Fractures in the elderly often lead to loss of mobility and independence, social alienation, fear of further falls and fractures, and depression. After hip fracture, most elderly patients fail to recover normal activity, and mortality within 1 year approaches 20%. Osteoporosis occurs when bone resorption outpaces bone formation. Underlying mechanisms are complex and probably diverse. Bone constantly undergoes cycles of resorption and remodeling to maintain the concentration of calcium and phosphate in the extracellular fluid. When serum calcium concentration drops, increased secretion of parathyroid hormone stimulates bone resorption by osteoclasts to restore serum calcium levels to normal. Bone mass declines with age and is influenced by sex, race, menopause, and weight-for-height. Dietary intake of calcium and vitamin D as well as intestinal and renal function affect calcium and phosphate homeostasis. The risk of osteoporosis is highest in postmenopausal women. Asian or white race, underweight, dietary calcium deficiency, sedentary lifestyle, alcohol use, and cigarette smoking appear to be independent risk factors. The decline of vitamin D3 level with aging results in calcium malabsorption, which, in turn, stimulates bone resorption. Estrogen deficiency exacerbates this problem by increasing the sensitivity of bone to resorbing agents. Female athletes who become amenorrheic because of rigorous exercise and dietary restriction or eating disorders are at risk of osteoporosis. The formation and resorption of bone are also influenced by external physical factors such as body weight and exercise. Immobilization and prolonged bed rest produce rapid bone loss, whereas exercise involving weight-bearing, resistance, and high impact has been shown both to reduce bone loss and to increase bone mass. Risk factors for osteoporosis in men include alcoholism, chronic lung disease, hypogonadism, and rheumatoid arthritis, and other disorders that restrict mobility. Osteoporosis is common in young adults with cystic fibrosis and in people receiving long-term thyroid hormone or glucocorticoid therapy. The diagnosis of primary osteoporosis is established by documentation of reduced bone density after exclusion of known causes of excessive bone loss. Assessment of bone density is currently recommended for all women 65 and older and for younger women who are at increased risk of osteoporosis. Roentgenograms are insensitive indicators of bone loss, because bone density must have decreased by at least 20-30% before the reduction can be appreciated. Standard diagnostic procedures are determination of bone mineral density (BMD) at the ultradistal radius and midshaft radius by single-photon absorptiometry (SPA) and at the hip and lumbar spine by dual-energy x-ray absorptiometry (DEXA). The World Health Organization defines osteoporosis as a BMD more than 2.5 standard deviations (SD) below the mean for healthy premenopausal women and osteopenia as a BMD between 1 and 2.5 SD below that level. A quantitative ultrasound procedure is comparable with bone density measurements by dual-energy x-ray absorptiometry in predicting fractures due to osteoporosis. The goal of therapy in osteoporosis is prevention of fractures in susceptible patients. The appropriate timing and proper use of agents such as calcium, vitamin D, estrogen, bisphosphonates, calcitonin, and raloxifene and the role of exercise have generated major research efforts and considerable controversy. Intake of adequate amounts of calcium and vitamin D, and continuing moderate weight-bearing exercise, are basic preventive measures for people of all ages. Those with demonstrated reduction of bone mineral density should take 1200-1500 mg of calcium and 400-800 IU of vitamin D daily. Administration of estrogen at and after menopause does not simply halt the loss of bone, but actually increases bone mass. However, to date there is no experimental proof that hormone replacement with estrogen reduces the risk of fractures in postmenopausal women. The possible benefits of estrogen therapy must be weighed against the increased risk of endometrial hyperplasia and endometrial carcinoma (which can be offset by concomitant administration of progestogen), myocardial infarction, stroke, invasive breast cancer, venous thromboembolism, and gallbladder disease. The selective estrogen receptor modulator raloxifene has been approved for prevention of osteoporosis. It does not cause endometrial hyperplasia but is less effective than estrogen in conserving bone mass. The hormone calcitonin, administered by injection or nasal spray, inhibits bone resorption. Bisphosphonates such as alendronate and etidronate, which bind to bone crystals, rendering them resistant to enzymatic hydrolysis and inhibiting the action of osteoclasts, have been shown to increase bone mineral density. In contrast to other agents, teriparatide, a synthetic version of the biologically active segment of human parathyroid hormone, actually stimulates bone formation in osteoporosis. Strategies to prevent falls are important in elderly patients. see also estrogen replacement therapy, raloxifene.

Farlex Partner Medical Dictionary © Farlex 2012


n. pl. osteoporo·ses (-sēz)
A disease characterized by a decrease in bone mass and density, occurring especially in postmenopausal women, resulting in a predisposition to fractures.

os′te·o·po·rot′ic (-rŏt′ĭk) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Brittle bones Orthopedics A condition characterized by ↓ bone mass and density–demineralization, bone fragility; it is the most common morbid condition of elderly ♀ Statistics Age-related osteoporosis causes > 105 fractures/yr–US–vertebrae 54%, hip 23%, distal forearm or Colles fracture, 17%; 25% of ♀ > 70 have evidence of vertebral fractures, as do 50% of ♀ > 80; 90% of femoral head fractures–FHFs occur in those > 70, US Clinical Pain, loss of height, other deformities and fractures Morbidity Osteoporosis-related fractures occur in 1.5 million/yr–US Risk factors White, elderly, ♀ thin, immobilization, space travel–weightlessness, extreme exercise and/or amenorrhea, alcoholism, endocrinopathies–eg, acromegaly, Cushing's disease, hypogonadism, hyperthyroidism, hyperparathyroidism, smoking Possible risk factors Heredity, inadequate exercise, ↓ Ca2+ intake, exercise, small body frame, levels of serum and urinary Ca2+ and creatinine; Pts receiving physiologic l-thyroxine may have ↓ bone density Diagnosis Bone densitometry, N-telopeptide measurement Treatment 1. Antiresorptive agents–eg, estrogen, calcium, calcitonin, biphosphonates and others eg anabolic steroids, calcitriol; K+ bicarbonate improves Ca2+ and phosphorous balance by ↓ hydroxyproline excretion–a marker of bone resorption, and ↑ osteocalcin–a marker of bone formation 2. Bone stimulation regimens–eg, sodium fluoride, PTH, and growth factors–eg, IGF-I, IGF-II, transforming growth factor-β and 3. Ca2+ supplementation–1000 mg/day, may slow axial and appendicular bone loss in postmenopausal ♀ See Congenital cranial osteoporosis, Malignant osteoporosis.
Osteoporosis–primary involutional  
Type I  or 'postmenopausal' osteoporosis A relatively common condition with a 6:1 ♀:♂ ratio, which affects ages 50-75, characterized by ↓ estrogen, accelerated trabecular bone loss, 'crush' fractures associated with abnormal PTH secretion and age-related ↓ in response to vitamin D 1,25(OH2D)2]; 15-20 years after the onset of menopause, type I osteoporosis may reach a 'burned-out' phase with no further bone loss
Type II or 'age-related' osteoporosis A less common condition with a 2:1 ♀:♂ ratio, which affects > age 70 and is characterized by trabecular and cortical bone loss–the elderly ♀ typically suffers a 35% loss of cortical bone and a 50% loss of trabecular bone, affecting vertebral bodies and flat bones, resulting in hip fractures and wedge-type vertebral fractures, due to 1. ↓ osteoblast function–↓ IGF-I, hGH, and local regulators 2. Marked ↓ in calcium absorption–to 50% of 'normal' with ↓ vitamin D 1,25(OH2D)2, possibly due to ↓ activity of renal 1-α hydroxylase and 3. Other factors, including ↓ clearance of parathyroid hormone's carboxyl–COOH terminals and ↑ calcium resorption; calcitonin's role in this form of osteoporosis is unclear
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


Reduction in the quantity of bone or atrophy of skeletal tissue; occurs in postmenopausal women and elderly men, resulting in bone trabeculae that are scanty, thin, and without osteoclasticresorption.
[osteo- + G. poros, pore, + -osis, condition]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(os?te-o-po-ro'sis) [ osteo- + -porosis]
Enlarge picture
OSTEOPOROSIS: deterioration of vertebral support due to osteoporosis
Loss of bone mass throughout the skeleton, predisposing patients to fractures. Healthy bone constantly remodels itself by taking up structural elements from one area and patching others. In osteoporosis, more bone is resorbed than laid down, and the skeleton loses some of the strength that it derives from its intact trabeculation. Aging causes bone loss in both men and women, predisposing them to vertebral and hip fractures. This is called type II osteoporosis (formerly “senile” osteoporosis). Type I osteoporosis (also known as “involutional” bone loss) occurs as a result of the loss of the protective effects of estrogen on bone that takes place at menopause. Synonym: bone loss; rarefaction of boneosteoporotic (-rot'ik), adjectiveillustration;


Several modifiable factors contribute to bone mass and strength: increased body weight, higher levels of sex hormones, and frequent weight-bearing exercise all build up bone and prevent fractures. Bone loss and the risk of fractures increase with age, immobilization, excess of thyroid hormone, use of corticosteroids and some anticonvulsant drugs, the consumption of alcohol, tobacco, and caffeine, and after menopause. Genetics (a nonmodifiable risk factor) also contributes to osteoporosis. See: table


Bone loss progresses for many years without causing symptoms. When it results in fractures, bone pain and loss of mobility may be disabling. Signs of osteoporosis include deformities of the skeleton, e.g., kyphosis (“dowager’s hump”), and loss of height, esp. if vertebral compression fractures occur.


Supplemental calcium and regular exercise help slow or prevent the rate of bone loss and are recommended for most men and women. Bisphosphonate drugs, e.g., alendronate, calcitonin, sodium fluoride, and other agents are useful for patients of both sexes. In menopausal women, estrogen supplementation or the selective estrogen receptor modulators help prevent bone loss and fractures, but calcium supplementation has not been shown to be helpful.

Patient care

Protection against osteoporosis should begin in childhood and adolescence and focus on building bone mass. Children should be encouraged to eat foods rich in calcium; parents should be taught to encourage regular exercise, including school gym classes and sports programs, to build strong bones and establish healthy habits. Parents should also be informed about the effects that eating disorders, excessive dieting, excessive exercise, alcohol consumption, and smoking have on bone density. From the mid-20s through age 35, focus continues to be placed on building and maintaining bone mass through a calcium-rich diet. After age 35, bone resorption exceeds bone formation. Emphasis is placed on preventing bone loss through a healthy diet, use of calcium (plus vitamin D) supplements (an intake of at least 1000 mg of calcium per day), and weight-bearing exercises, e.g., weight-lifting, walking, jogging, dancing, and climbing stairs. High-impact aerobics may create too much stress on the bones of older adults and should be avoided.

After patients have been diagnosed with osteoporosis, time should be spent assessing their diets and activity levels. Although patients should engage in walking or other weight-bearing activity for 30 to 60 min three to four times a week, this goal may need to be approached slowly. Foods rich in calcium include dairy products, spinach, sardines, and nuts. Calcium supplements totaling 1000 to 1500 mg per day should be consumed and can prevent further bone loss. Based on bone density testing, alendronate or another drug that inhibits bone resorption may be prescribed in a daily or weekly formulation. Bisphosphonates like alendronate should be taken on an empty stomach with a full glass (8 oz) of water. The patient should remain in an upright position for 30 min after taking these medications to avoid pill-induced esophagitis.


The National Osteoporosis Foundation (NOF) and the World Health Organization (WHO) recommend tests to determine bone mineral density, e.g., dual energy x-ray absroptiometry (DEXA scanning) in patients with specific diseases or conditions. The NOF recommends that all women over 65 and all men over 70 undergo testing. The NOF also recommends bone density testing for anyone over 50 who fractures a bone and for women of menopausal age who have risk factors (see Table "Risk Factors for Osteoporosis").

osteoporosis circumscripta cranii

Localized osteoporosis of the skull associated with Paget's disease.

osteoporosis of disuse

Osteoporosis due to the lack of normal functional stress on the bones. It may occur during a prolonged period of bedrest or as the result of being exposed to periods of weightlessness, e.g., astronauts in outer space.

glucocorticoid osteoporosis

Bone loss that results from prolonged treatment with oral or inhaled steroids, e.g., prednisone, beclomethasone, or triamcinolone.

idiopathic juvenile osteoporosis

Juvenile osteoporosis.

juvenile osteoporosis

A rare childhood disease of inadequate bone mineral density, characterized by poor bone formation that usually improves spontaneously during puberty or young adulthood. Affected children often complain of bone or back pain, muscle weakness, or impaired gait. Fractures of long bones and vertebral compression fractures are common. Other diseases of bone formation, such as osteogenesis imperfecta, must be excluded before a diagnosis of juvenile osteoporosis is made. Affected children are usually asked to refrain from participation in sports to lessen the risk of fractures. Synonym: idiopathic juvenile osteoporosis

post-traumatic osteoporosis

Loss of bone tissue following trauma, esp. when there is damage to a nerve supplying the injured area. The condition may also be caused by disuse secondary to pain.
SOURCE: Stanley, M and Beare, PG: Gerontological Nursing, FA Davis, Philadelphia, 1995. National Osteoporosis Foundation website, 2011.
Advanced age
White or Asian
Thin, small-framed body
Positive family history
Low calcium intake
Early menopause (before age 45)
Sedentary lifestyle
Excessive alcohol or caffeine intake
High protein intake
High phosphate intake
Certain medications, when taken for a long time (e.g., aromatase inhibitors, glucocorticoid, phenytoin, proton pump inhibitors, selective serotonin reuptake inhibitors, thiazolidinediones, thyroid medication)
Endocrine diseases (hyperthyroidism, Cushing's disease, acromegaly, hypogonadism, hyperparathyroidism)
Diseases such as anorexia nervosa, autoimmune disorders, celiac disease, HIV/AIDS, multiple myeloma, multiple sclerosis, Parkinson disease, sickle cell disease
Medical Dictionary, © 2009 Farlex and Partners


A form of bone atrophy involving both the COLLAGEN scaffolding and the mineralization. WHO has defined osteoporosis as bone mineral density that is 2.5 standard deviations or more below the normal mean value for young adults. It is thought to be due to predominance of reabsorption of bone over natural bone formation with resulting loss of architecture and structural strength. It is commonest in women after the menopause and tends to be progressive, giving rise to the high risk of fractures from minimal trauma. Osteoporosis has many causes, the most important being long-term disuse and loss of sex hormones. Other causes include overactivity of the thyroid and parathyroid glands, CUSHING'S SYNDROME, malnutrition and prolonged treatment with corticosteroid drugs. Assessment is by bone densitometry. The progress of osteoporosis can be reduced in women by HORMONE REPLACEMENT THERAPY and by BISPHOSPHONATE drugs and calcium supplements. In some cases fluoride or ANABOLIC STEROIDS are recommended.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


a condition in which there is a loss of bony tissue, leading to bones that are brittle and prone to fracture. Osteoporosis is common in the elderly and in women after the MENOPAUSE.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005


Reduction in the quantity of bone or atrophy of skeletal tissue; a widespread age-related disorder characterized by decreased bone mass and loss of normal skeletal microarchitecture, leading to increased susceptibility to fractures.
[osteo- + G. poros, pore, + -osis, condition]
Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about osteoporosis

Q. Is osteoporosis preventable? My mother had osteoporosis and I already have osteopenia which may lead to it. How can I prevent it??

A. Prevention of osteoporosis, in it's strict sense, is done mainly during childhood through early adulthood (third decade) - the years during which the peak bone density is determined. At older age, treatment of osteoporosis, apart from medications, include vitamin D and calcium supplementation, physical activity and avoiding smoking and excess alcohol consumption.

There are also medications to treat osteoporosis, mainly from the bisphosphanate class. However, remember to consult your doctor before you make any change in your diet or start exercise program.

You may read more here:

Q. My mom have seen her bad days with osteoporosis. My mom have seen her bad days with osteoporosis. I know her pain during winter where she cannot make herself move every morning. I have been seeing her for many years on medications. Looking over my mom`s condition I started to keep myself fit. This will help to control the future chances of osteoporosis for me. I have heard that it runs in families. I do jogging but I was concerned as is this enough?

A. Generally osteoporosis starts with bone loss and this bone loss starts after the person crosses his mid 30`s. Weight can increase the osteoporosis symptoms. So you must do some weight bearing exercise. Like gardening, aerobics, climbing, brisk walking. Though you must eat well. Do eat good diet rich in vitamin D. also have green leafy vegetables and milk as well. This diet must be increased once you are over the age of 30.

Q. I am excited to know in what way diet helps in preventing osteoporosis? my mother is suspecting to be having osteoporosis. She regularly complains of leg pain. Upon consultation with the doctor it was found with low calcium in her blood. She was given calcium tablets and was told to increase in the diet rich in calcium. She is taking milk and yoghurt especially. She is not well yet but shows some improvement. I am excited to know in what way diet helps in preventing osteoporosis?

A. you see, our bones are a giant storage of calcium. our body needs a very steady concentration of calcium, if it'll be low the body will take it form your bones. if there's too much- it'll either build bones (but only if he'll think he needs too- that is where sport get in the picture)or you'll urinate it.any way, you rather have large amount of calcium in your diet then less. but it's not enough- sport and other medication can help.

More discussions about osteoporosis
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References in periodicals archive ?
Furthermore, previous studies assessed the isometric muscle strength in patients with postmenopausal osteoporosis, particularly back strength.
The results of this study in Chinese postmenopausal females not affected by diabetes showed that NLR level may be a risk factor for osteoporosis and further studies were warranted to investigate the potential relationship between NLR and bone loss in other population and to confirm that NLR could become a helpful clinical tool in the assessment of postmenopausal osteoporosis.
Potential first-line therapies for postmenopausal osteoporosis can be use of agents that inhibit bone resorption, thereby improving bone strength and reducing osteoporotic fracture (Akesson 2003; Josse et al.
Raloxifene (Evista) is an estrogen agonist/antagonist (formerly known as a SERM) approved for the prevention and treatment of postmenopausal osteoporosis. (45) It has been shown to reduce the risk of vertebral fractures and has an advantage over BPs in that it can be taken at any time of day.
It is indicated for use in men with osteoporosis, women with postmenopausal osteoporosis, and for patients with GIO.
Oestrogen treatment of patients with established postmenopausal osteoporosis. Obstetrics and gynaecology.1990;76:290-5.
Tarsa Therapeutics has completed its global Phase III ORACAL trial with once-daily oral recombinant calcitonin for the treatment of postmenopausal osteoporosis. The multinational, randomized, double-blind, active and placebo-controlled Phase III trial enrolled 565 postmenopausal women with osteoporosis.
Four bisphosphonates--alendronate, ibandronate, risedronate, and zoledronic acid--are approved by the US Food and Drug Administration (FDA) for the treatment of postmenopausal osteoporosis.
Postmenopausal osteoporosis is a common problem that accounts for significant morbidity and diminished quality of life among middle-aged women.
Vitamin K2, raloxifene, and bisphosphonates, such as etidronate, alendronate, and risedronate, are widely used in the treatment of postmenopausal osteoporosis in Japan.
This new medicine will provide an important therapeutic option in the treatment of postmenopausal osteoporosis in women at increased risk of fractures.
"In particular, we believe that Prolia will offer patients with postmenopausal osteoporosis at increased risk for fracture an important alternative to current treatments.