These tests are the only way to reveal bone health before fracture occurs.
You might associate certain symptoms with osteoporosis, like frailness or a stooped posture, but the truth is, those characteristics don’t develop until osteoporosis has reached an advanced stage. In the earlier stages of osteoporosis, the disease is much more silent.
“The only way to know if you have osteoporosis is by doing a bone density test,” says Sonal Chaudhry, MD, endocrinologist at NYU Langone Health. There’s one exception: “If you’ve had a fragility fracture in the past, that by definition means that you do have osteoporosis.”
Bone Density Tests for Osteoporosis
A bone density test is an X-ray that estimates how dense your bone mineral is, which can reveal your risk of fractures. For most people, doctors recommend bone density tests for all women over age 65 and men over age 70, according to the National Osteoporosis Foundation.
Those recommendations vary based on your personal risk factors. “If you’re menopausal, and you’re between the ages of 50 and 65, and you have risk factors, it’s also appropriate to do bone density testing,” says Dr. Chaudhry.
Risk factors for osteoporosis include:
History of eating disorders
History of skipped periods
Family history of osteoporosis
Inflammatory bowel disease
Or consuming more than two alcoholic drinks a day.
Having any risk factors for osteoporosis could make you eligible for a bone density test as early as age 50.
Understanding Bone Density Test Results
A bone density test will provide a T-score and a Z-score. The T-score compares your bone density to that of a younger, healthy adult; a Z-score compares your bone density to what is normal in someone your age and body size.
Here’s how doctors interpret a T-score from a bone density test:
A T-score greater than -1 indicates a normal bone density.
A T-score between -1 and -2.5 indicates low bone mass, known as osteopenia. Your doctor may recommend certain lifestyle habits to manage osteopenia.
A T-score lower than -2.5 indicates osteoporosis. Your doctor will recommend treatment for osteoporosis to reduce your risk of fracture.
Your T-score may not tell the whole story, especially for younger people (such as women who are still having periods). This is when Z-scores may be more informative.
If someone has a Z-score below -2.5, doctors will likely look for secondary causes of low bone density, such as:
Or excess calcium excreted through the urine.
“Screening is really important because you don’t ‘feel’ osteoporosis,” says Dr. Chaudhry. “You don’t know that it’s there unless you have the test—unless you have a fracture.”
00:00:00,000 --> 00:00:03,064
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So osteoporosis in and of itself
doesn't cause any symptoms until or
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unless you unfortunately fracture.
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So the only way to know if you have
osteoporosis is by doing a bone
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Or if you've had a fragility
fracture in the past,
00:00:17,305 --> 00:00:20,763
that by definition means that
you do have osteoporosis
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00:00:27,973 --> 00:00:31,607
In the absence of risk factors,
all women over the age of 65 and
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all men over the age of 70 should
have screening bone density tests.
00:00:35,593 --> 00:00:38,782
If you're menopausal and
in between the ages of 50 and 65 and
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you have risk factors, it's also
appropriate to do bone density testing.
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People who are considered highest risk
are women who have gone through menopause
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early, women who have a history
of either disordered eating or
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skipped periods when they were younger.
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Women who have a family history of
osteoporosis, if you have celiac disease,
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inflammatory bowel disease,
if you're a smoker you're at higher risk.
00:00:59,680 --> 00:01:03,502
If you drink more than two drinks a day,
you're considered at higher risk.
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So a bone density test is
similar to an X-ray and
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it's giving you a sense of
what your fracture risk is.
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It's measuring a T-score and a Z-score.
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So the T-score is a parameter that is
comparing you to a young healthy adult.
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And so if your T-score is greater than -1,
that's considered normal bone density.
00:01:24,000 --> 00:01:29,310
If your T-score is between -1 and
-2.5, that's low bone mass or
00:01:29,310 --> 00:01:33,760
osteopenia, which in and of itself doesn't
increase your risk of fracture, but
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certainly does increase
your risk of osteoporosis.
00:01:36,518 --> 00:01:42,740
If your T-score is less than -2.5,
it's consistent with osteoporosis.
00:01:42,740 --> 00:01:48,170
The Z-score is comparing your bone
density to an age-matched peer.
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And if you have a low Z-score,
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which is characterized by
a Z-score that's less than -2,
00:01:54,900 --> 00:01:59,110
then we look for secondary causes that may
be contributing to your low bone density.
00:01:59,110 --> 00:02:03,740
We may look for things like
hyperthyroidism or hyperparathyroidism.
00:02:03,740 --> 00:02:08,370
We may wanna make sure you don't have
a hematologic problem that's contributing,
00:02:08,370 --> 00:02:11,860
or that you're not excreting
too much calcium in your urine.
00:02:11,860 --> 00:02:15,400
Screening is really important
because you don't feel osteoporosis.
00:02:15,400 --> 00:02:19,104
You don't know that it's there unless you
have the test, unless you have a fracture.
00:02:19,104 --> 00:02:25,427
Bone density exam/testing. Arlington, VA: National Osteoporosis Foundation. (Accessed on February 25, 2019at https://www.nof.org/patients/diagnosis-information/bone-density-examtesting/.)
Bone mass measurement: what the numbers mean. Bethesda, MD: National Institute of Arthritis and Musculoskeletal and Skin Diseases. (Accessed on February 25, 2019 at https://www.bones.nih.gov/health-info/bone/bone-health/bone-mass-measurement-what-numbers-mean.)