You may not notice symptoms of osteoporosis until you break a bone, notice a loss in height or find that your upper back bends forward. However, your doctor has ways to determine if you have osteoporosis or are at risk for it. Your doctor may ask questions about your medical history with particular attention to your overall health, medications, fractures, diet and family history. You may need a physical examination and blood and urine tests to rule out other diseases that weaken bones.

If you are at risk for developing osteoporosis, or already show signs of it, your doctor will probably order a bone density test. This test is the best way to predict the risk of fracture if you have not already broken a bone. It helps diagnose osteoporosis, particularly in the disease's early stages before fractures have occurred.

Getting an accurate measure of bone density can help you and your doctor evaluate the need for preventive measures and treatment. This should be done in all women who have experienced menopause; those who are taking glucocorticoids; anyone who shows suspicious spine fractures; and those who have diseases that affect calcium. This test is also used to monitor osteoporosis prevention and treatment.

Bone measurement is a quick, painless and inexpensive test. The most accurate of these tests is done with a bone densitometer using dual-energy X-ray absorptiometry (DXA). The DXA scan is very accurate and can measure as little as one percent loss of bone. The DXA scan is used to diagnose bone loss as well as document bone density over time and with treatment.

Special CT scans can also measure bone density and ultrasound machines may be helpful in the near future. Routine X-rays of the bones help identify fractures. However, X-rays are not accurate in determining bone density, because 30 percent or more of the bone must be lost before the X-ray shows it clearly. Other densitometry methods are useful, but less accurate.

Your doctor also may conduct a variety of laboratory tests to help rule out secondary contributing factors to osteoporosis. These include serum calcium, phosphorus, protein, thyroid hormone, alkaline phosphatase, and liver and kidney function tests.