Because routine x-rays can't detect osteoporosis until it has become advanced, the most common test used for making a diagnosis is a bone mineral density test (known as a dual-energy x-ray absorptiometry, or DEXA test). In addition to making a diagnosis, this test can predict your likelihood of fractures and determine your rate of bone loss. No symptoms (other than a bone fracture) indicate osteoporosis.
Osteoporosis is often called the "silent disease" because bone loss occurs without symptoms. Therefore, an osteoporosis diagnosis often occurs after a sudden strain, bump, or fall causes a hip to fracture or a vertebra to collapse.
Routine x-rays can't detect osteoporosis until it's quite advanced.
Bone density tests are useful for diagnosing osteoporosis if a person has already had a suspicious fracture, or for detecting low bone density so that preventive steps can be taken.
Following a medical exam and assessment of risk factors, your doctor may recommend that you have your bone mass measured. A bone mineral density (BMD) test is the best way to determine your bone health. BMD tests can be used in diagnosing osteoporosis by determining your risk for fractures (broken bones) and measuring your response to osteoporosis treatment.
The most widely recognized bone mineral density test is called a dual-energy x-ray absorptiometry, or DEXA test. It is painless -- like having an x-ray, but with much less exposure to radiation. It can measure bone density at your hip and spine. Bone density tests can:
- Detect low bone density before a fracture occurs
- Confirm an osteoporosis diagnosis if you already have one or more fractures
- Predict your chances of having fractures in the future
- Determine your rate of bone loss
- Monitor the effects of treatment if the test is conducted at intervals of a year or more.
The results of the DEXA test are scored in comparison to the BMD of young, healthy individuals, resulting in a measurement called a T-score. If your T-score is -2.5 or lower, you are considered to have osteoporosis and are, therefore, at high risk for a fracture.
T-scores between -1.0 and -2.5 are generally considered to show osteopenia (a reduction in bone mass that is less severe than osteoporosis). The risk of fractures is generally lower in people with osteopenia when compared to those with osteoporosis, but if bone loss continues, the risk for fracture increases.
If you are age 65 or older, you should get a bone density test. If you are between the ages of 60 and 64, weigh less than 154 pounds, and don't take estrogen, get a bone density test right away -- don't wait until age 65. You have a higher chance for fractures.