What Is Osteoporosis?
Osteoporosis (meaning porous bone) is a bone disease in which bone loss occurs, so that bones become weak and are more likely to break. Without prevention or treatment, osteoporosis can progress without pain or symptoms until a bone breaks (fractures). Fractures from osteoporosis commonly occur in the hip, spine, ribs, and wrist.
What Causes Osteoporosis?
Bones may seem like hard and lifeless structures, but they are in fact living tissue. Bone is constantly broken down and remodeled (through a process called bony resorption) by our bodies, while new bone is simultaneously deposited. When bone is broken down faster than it is deposited, low bone mass (osteopenia) and osteoporosis can occur.
What Are Osteoporosis Symptoms and Signs?
In many people, low bone mass (osteopenia) and osteoporosis occur without any symptoms. In people with osteoporosis, a simple everyday movement, such as picking up a grocery bag, can cause a sudden onset of back pain, and that can be the first symptom. As osteoporosis progresses over a period of time, the bony building blocks of the spine (vertebrae) can begin to collapse. Collapsed vertebrae may be felt as severe back pain or cause a loss of height or spinal deformities. When the spinal vertebrae collapse in the upper back, it can lead to a hump of curvature (dowager's hump). The most common bones broken in osteoporosis are the hip, spine, wrist, and ribs, although any bone in the body can be affected by osteoporosis and can break. Spinal fractures can cause permanent loss of height.
When Does Osteoporosis Occur?
Osteoporosis can occur at any age. However, it is more common in people older than 50 years of age, and the older a person is, the greater the risk is of osteoporosis. This is because during childhood and teenage years, new bone is generally added faster than old bone is removed. This is the time when a diet rich in calcium, phosphate, and vitamin D is important. As a result, bones become larger, heavier, and denser. Maximum bone density and strength is reached by 20-25 years of age. The density and strength of the bones is fairly stable from 25-45 years of age. A slight loss of bone density begins to occur after age 30 because bone slowly begins to break down (a process called resorption) faster than new bone is formed. For women, bone loss is fastest in the first few years after menopause, but it continues gradually into the postmenopausal years. As bone density loss occurs, osteoporosis can develop. This process is slower by 10 years in men.
Main Types of Drugs
There are two main types of drugs: antiresorptive drugs that slow the progression of bone loss and bone-building agents that help increase bone mass. Antiresorptive drugs are already widely available. Bone-building drugs are being developed by researchers and are just becoming available.
Who Is at Risk for Osteoporosis?
Certain risk factors are associated with developing osteoporosis. Many people with osteoporosis have several risk factors, but some people with osteoporosis have none. Some risk factors cannot be changed. These include the following:
- Gender: Women are more likely to develop osteoporosis than men.
- Age: The older a person is, the greater the risk of osteoporosis.
- Physical build: People who are small and have thin bones are at greater risk.
- Race: White and Asian women are at the highest risk.
- Family history: If a person's parents had osteoporosis, he or she may be at risk.
Some risk factors can be modified. These include the following:
- Levels of sex hormones: Low estrogen in women, particularly after menopause, and low testosterone in men are associated with osteoporosis.
- Anorexia, diet: Diets low in calcium, phosphate, and vitamin D are risk factors.
- Use of medications: Glucocorticoids, which are medications prescribed for a wide range of diseases, including arthritis, asthma, Crohn's disease, lupus, and other diseases, can cause osteoporosis.
- Inactive lifestyle
- Cigarette smoking
- Excessive alcohol intake
You can also take the 1-minute osteoporosis risk test from the International Osteoporosis Foundation.
How Is Osteoporosis Detected?
Unfortunately, many people do not know they have osteoporosis until they experience a broken bone. By that time, bones are already weak. However, osteoporosis can be prevented or delayed by early detection and treatment. Specialized tests called bone density tests can measure bone density (solidness) in various sites of the body, such as the hip, spine, and wrist. These tests are quick (taking less than 15 minutes), painless, and noninvasive and are extremely helpful in screening for and making a diagnosis of osteoporosis. This bone density measurement provides a quantitative assessment, called a T-score, which can be used for diagnosis and monitoring during management. A bone density test can detect osteoporosis before a fracture occurs and can predict your chances of having a broken bone in the future. A dual-energy X-ray absorptiometry (DXA) scan of bone mineral density (BMD) can determine your rate of bone loss and/or be used to monitor the effects of treatment. Talk to the doctor about these tests.
Which Health-Care Professionals Treat Osteoporosis?
Health-care professionals who treat osteoporosis include primary-care physicians, such as doctors of general medicine, family practitioners, internists, as well as gynecologists, rheumatologists, endocrinologists, physiatrists, and orthopedic surgeons. Additional providers of treatments for osteoporosis include physical therapists, nutritionists, and occupational therapists.
What Is the Treatment for Osteoporosis?
Osteoporosis treatment includes both lifestyle changes and medications. Treatment programs focus on nutrition, physical exercise, and safety issues to prevent falls that may result in broken bones. Supplemental calcium and vitamin D are basic keys to the management of both osteopenia and osteoporosis. The doctor may prescribe a medication to slow or stop bone loss, increase bone density, and reduce fracture risk. Available oral medications include alendronate (Fosamax), raloxifene (Evista), ibandronate (Boniva), and risedronate (Actonel) for preventing and treating postmenopausal osteoporosis. Zoledronate (Reclast) is a once-yearly intravenous infusion for preventing and treating postmenopausal osteoporosis. Teriparatide (Forteo) is a self-injectable medication used to treat osteoporosis in postmenopausal women and men. Alendronate can also be used to treat osteoporosis in men. Glucocorticoid-induced osteoporosis is treated by alendronate and risedronate in men and women.
Other medications, including estrogen or hormone replacement therapy (ET/HRT), are used to prevent postmenopausal osteoporosis, and calcitonin is approved for treatment. Talk to the doctor about these medications.
What Are Complications of Osteoporosis?
The major complication of osteoporosis is fracture of bone. Depending on what bones fracture and how they fracture, there can be further complications. For example, if a spinal vertebra in the low back is collapsed by a compression fracture, this can cause bone to directly press against nervous tissue of the spinal cord, causing severe pain and loss of function of the lower extremities. Collapse of vertebrae in the upper back (thoracic vertebrae) can cause breathing to be difficult.
What Is the Prognosis for Patients With Osteoporosis?
With early treatment, the prognosis is better than with later treatment. Severe osteoporosis is dangerous. The key to optimal management of osteoporosis is detecting it as early as possible. Current bone density testing is a simple screening method that can be used to find thinning of bone. The medications now available to treat osteoporosis substantially reduce the risk of fractures in patients with osteoporosis.
Is It Possible to Prevent Osteoporosis?
Osteoporosis is preventable by reaching the peak bone mass (maximum bone density and strength) during the childhood and teenage years and by continuing to build more bone as one gets older, particularly after the age of 30. A few things that can be done to maintain healthy bone are as follows:
- Get enough calcium and vitamin D by drinking milk or eating milk products in a healthy diet.
- Do physical exercise.
- Do not smoke.
- Avoid excessive intake of alcohol.
Be aware that long-term use of some medications such as glucocorticoids (medications prescribed for a wide range of diseases, including arthritis, asthma, Crohn's disease, lupus, and other diseases of the lungs, kidneys, and liver) can lead to a loss of bone density. Contact the treating doctor to discuss either prevention or treatment of osteoporosis under these circumstances.
Other drugs that can cause bone loss include certain antiseizure drugs, such as phenytoin (Dilantin) and barbiturates, gonadotropin-releasing hormone (GnRH) analogs used to treat endometriosis, excessive use of aluminum-containing antacids, certain cancer treatments in both men and women, and excessive thyroid hormone. Talk to the doctor. Also, talk to the doctor about the many medications that are available to delay or prevent osteoporosis.
The image on the left shows decreased bone density in osteoporosis. The image on the right shows normal bone density. Arrow indicates vertebral fractures. A. Normal spine, B. Moderately osteoporotic spine, C. Severely osteoporotic spine.
Reviewed on 11/17/2017
Klippel, J.H., et al. Primer on the Rheumatic Diseases. New York: Springer, 2008.