Diagnosing osteoporosis starts with a physical exam and a careful medical history and may include other diagnostic tests.
The U.S. Preventive Services Task Force, an independent panel of experts in prevention, recommends that all women age 65 and older be screened for osteoporosis. The task force also recommends that routine screening begin at age 60 for women at increased risk for fractures due to osteoporosis (for instance, those who have additional risk factors).
If you have not been checked for osteoporosis and you are a woman over age 65, or if you suspect that you have significant risk factors for the disease, you may want to talk to your doctor about being evaluated. For example, if you are over 50 and have broken a bone, you may have osteoporosis or be at increased risk for the disease. You should also ask your doctor about osteoporosis if you notice that you have lost height or your posture has become stooped or hunched, or if you experience sudden back pain.
When asking about your medical history, your doctor will ask questions to find out whether you have risk factors for osteoporosis and fractures. The doctor may ask questions about any fractures you have had, your lifestyle (including diet, exercise, and smoking history), medications, your family history of osteoporosis and other medical conditions, and, for women, your menstrual history. Your doctor will also perform physical exam that may include checking for a loss of height and changes in posture.
If you report back pain or have signs of vertebral fractures, your doctor may order an x-ray of your spine to look for spinal fractures or malformations due to osteoporosis. (X-rays are not very effective at detecting osteoporosis).
Laboratory tests may be ordered to identify conditions that may be contributing to bone loss, such as hormonal problems or vitamin D deficiency. The most common blood tests evaluate blood calcium levels, blood vitamin D levels, thyroid function, parathyroid hormone levels, and other hormone levels. Urine tests, such as 24-hour urine collection, may be ordered help to measure calcium metabolism and measure the rate at which a person is breaking down or resorbing bone.
Bone Mineral Density (BMD) Testing
If the results of your physical exam, medical history, x rays, or laboratory tests indicate that you may have osteoporosis or that you have significant risk factors for the disease, your doctor may recommend a bone density test.
A bone mineral density (BMD) test is the best way to determine your bone health. It painlessly measures bone density at your hip and spine.
Bone mineral density tests can determine your risk for fractures, and measure your response to osteoporosis treatment.
The most widely used bone mineral density test is called a dual-energy x-ray absorptiometry, or DXA test. Although no bone density test is 100% accurate, this type of test is the single most important predictor of whether a person will have a fracture in the future.
During a bone mineral density test, an extremely low energy source is passed over part or all of the body. A computer program evaluates the information and allows the doctor to see how much bone mass you have. Because bone mass serves as an approximate measure of bone strength, this information also helps the doctor to detect low bone mass accurately, make a definitive diagnosis of osteoporosis, and determine your risk of future fractures.
Reference: The National Institute of Arthritis and Musculoskeletal and Skin Diseases