
Osteoporosis is a disorder of the bones in which the bones become brittle, weak, and easily damaged or broken. A decrease in the mineralization and strength of the bones over time causes osteoporosis.

While the effects of osteoporosis are often seen in the elderly, the disorder usually starts progressing from middle age on. Bones are their strongest in a person's mid-twenties, so it is important to have a good foundation early on to maintain healthy bones late in life.

In the United States, 10 million people have osteoporosis (80% of those are women), and 34 million are at risk for developing the disease due to low bone density. Osteoporosis is a public health issue because the disease contributes to 1.5 million fractures (broken bones), including 350,000 hip fractures annually. The costs of medical care for these injures was an estimated $17 billion in 2005. These injuries can also result in permanent disability or an inability to return to work or perform daily activities.

Osteoporosis may not cause any apparent symptoms. Patients may not know they have osteoporosis until they break (fracture) a bone.

Vertebral (spinal) compression fractures are broken bones in the back that are due to weak bones caused by osteoporosis. The vertebrae (spinal bone) collapses as a result of even minor injuries related to falling, bending, twisting, or sneezing. As the bones of the spine lose their mineralization and strength, they can collapse, causing a hunched-over appearance, often referred to as a "dowager hump."

Stress fractures occur in bones due to repetitive injuries, usually with minimal trauma. Patients with osteoporosis are more prone to stress fractures because of the weakness of their bones.

Patients with osteoporosis are at greater risk for hip fractures. Even a simple fall can cause a hip fracture in a person with osteoporosis. Due to the weakness in the bones these injuries may take a long time or be difficult to fully heal.

Fractures related to osteoporosis can result in significant pain and disability. Hip fractures are common among patients with osteoporosis. Twenty percent of hip fracture patients die within one year following their injury, and one-third will remain in a nursing home for at least a year.
Patients who have one vertebral (spinal) compression fracture are at high risk for developing other such fractures.

Bone strength is related to bone mass (density), which refers to the amount of mineralization remaining in bones as people age. The denser the bones, the stronger they are.
Factors that determine bone strength include:

Women tend to be diagnosed with osteoporosis more often than men because once they reach menopause estrogen levels decrease. Estrogen helps maintain bone density in women. Post-menopausal women can lose up to 4% of bone mass annually in the first 10 years following menopause.

Risk factors for developing osteoporosis that cannot be controlled include:
Risk factors for developing osteoporosis that can be controlled include:

Additional risk factors for developing osteoporosis include medical conditions such as:

Osteoporosis is often diagnosed on an X-ray when the patient suffers a fracture. However, by the time osteoporosis is visible on X-ray there may be significant bone loss.
A dual energy X-ray absorptiometry (DEXA or DXA) scan can be used as a screening test for osteopenia (bone loss that precedes osteoporosis). This test measures bone density in the hip and spine and is more precise than an X-ray.

The National Osteoporosis Foundation recommends the following groups of people should have dual energy X-ray absorptiometry (DEXA or DXA) scans to screen for osteoporosis:

The DXA scan lists results as a "T score." This measurement is a statistical comparison (SD, or standard deviation) of the patient's bone density compared to the average peak bone density of a young adult of the same gender and ethnicity.

There is no current cure for osteoporosis. Osteoporosis treatment involves stopping further bone loss, and strengthening bones that show signs of weakness. Prevention of osteoporosis is key.

Exercise is important in helping improve muscle strength and balance, which can decrease falls and other accidents. Weight-bearing exercise also has the benefit of helping to strengthen bones. Consult your doctor for the type and duration of exercise that is right for you.
