Of all the conversations I have in my Menlo Park practice, the ones about bone health are among the most charged. A woman receives a DEXA result, sees a number like negative 2.8, and leaves with a diagnosis of severe osteoporosis and a prescription in hand. She is frightened. She starts medication. And nobody has told her that the test she just had is a two-dimensional measurement of a three-dimensional structure, significantly influenced by her body size, that cannot distinguish between the two types of bone tissue and does not measure the one thing that actually determines whether she will fracture: bone quality.
I recently wrote about a case that illustrates this perfectly. An orthopedic surgeon shared a story with me about his wife, a petite woman with a severe DEXA diagnosis who fell on ice multiple times and broke nothing. Her REMS scan explained why. If you want to start there, read the companion piece first: She Fell on Ice Multiple Times and Broke Nothing. Her DEXA Said She Should Have.
What follows is the clinical framework behind that story. Why DEXA has the limitations it does, why those limitations matter most for women in perimenopause and menopause, and what REMS measures that changes the picture entirely.
Key Highlights
- Bone loss accelerates significantly during perimenopause and the first years after menopause, which is when most women receive their first DEXA scan
- DEXA measures bone mineral density, which is an important but incomplete picture of fracture risk
- DEXA results are significantly influenced by body size, meaning small thin women are frequently over-diagnosed with osteoporosis
- The 2025 International Osteoporosis Foundation Position Paper acknowledges that many people who fracture have normal or only modestly reduced bone mineral density
- REMS uses ultrasound rather than radiation, measures both bone density and bone quality, and produces a Fragility Score that is independent of body size
- Hormones, blood sugar, vitamin D, omega-3 levels, and inflammatory burden all directly influence bone health and must be addressed alongside any bone scan result
- REMS bone assessments are coming to Wellness Architecture this September
Why Perimenopause and Menopause Change Everything for Bone Health
Estrogen is one of the most important regulators of bone metabolism in women. It directly suppresses osteoclast activity, meaning it slows the rate at which old bone is broken down. When estrogen begins to decline in perimenopause, that brake is released. Bone resorption accelerates. The rate of bone turnover increases. And women can lose a significant amount of bone density in a relatively short window of time.
The research is consistent on this: women can lose between 10 and 20 percent of their bone density in the first five to seven years after menopause. This is why bone health becomes a clinical priority in the perimenopausal years and why most women receive their first DEXA scan in their late 40s or 50s. It is also why the results of that first scan carry so much weight, sometimes too much weight, in the decisions that follow.
What most women are not told is that the hormonal picture is considerably more complex than estrogen alone. Progesterone plays a direct role in stimulating osteoblast activity, which is the bone-building side of the equation. When progesterone declines in perimenopause, often before estrogen does, the balance between bone breakdown and bone building can shift even before a woman's cycles become irregular. This is one reason I see perimenopausal women in their mid-40s already showing early bone changes that their conventional doctors are not yet looking for.
Cortisol matters too. Chronically elevated cortisol, which is extremely common in the high-functioning, high-stress women I see across the Bay Area Peninsula, directly inhibits osteoblast function and accelerates bone loss. A woman who has been running on cortisol for a decade going into perimenopause is not starting from the same baseline as someone whose stress physiology has been well-managed. Her bones have already been under pressure before the hormonal shift begins.
And then there is the thyroid. Hyperthyroidism, including subclinical hyperthyroidism that often goes undiagnosed, increases bone turnover and is an independent risk factor for fracture. Women with unaddressed thyroid dysfunction going into menopause are at greater bone risk than their DEXA alone will reveal. This is one of many reasons a bone scan result cannot be read in isolation from the rest of a woman's clinical picture.
What DEXA Actually Measures
DEXA, which stands for dual-energy X-ray absorptiometry, has been the clinical standard for osteoporosis diagnosis since the 1990s. It measures bone mineral density at the lumbar spine, hip, and sometimes forearm, and produces a T-score that compares your density to that of a healthy young adult. A T-score of negative 2.5 or lower gets you a diagnosis of osteoporosis. Between negative 1.0 and negative 2.5 is osteopenia.
For the majority of women who receive a DEXA scan in their 50s, this is their first formal assessment of bone health. It often comes after a conversation about menopause, after a fracture scare, or as part of a routine workup. The number feels authoritative. The diagnosis feels definitive. And the recommended treatment, usually a bisphosphonate, often follows quickly.
The problem is not that DEXA is wrong. The problem is that bone density is not the same thing as bone strength. And bone strength is what actually determines whether you fracture when you fall.
A 2025 Position Paper from the International Osteoporosis Foundation made this explicit: many individuals who fracture have normal or only modestly reduced bone mineral density. The field is now moving toward calculating absolute fracture risk using multiple clinical factors, rather than relying on a single density measurement to determine who needs treatment. This is a significant shift in the official position of the world's leading osteoporosis organization, and it reflects what clinicians who look closely at this issue have known for years.
DEXA also has well-documented technical limitations. It is a two-dimensional measurement of a three-dimensional structure. It cannot distinguish between cortical bone, the hard outer shell, and trabecular bone, the inner spongy network where most fractures actually originate. It is meaningfully influenced by body size, positioning during the scan, the experience of the technician, and the presence of degenerative changes in the spine that can artificially inflate the density reading. A woman with arthritis in her lumbar spine may get a falsely reassuring result. A woman who weighs 105 pounds may get a falsely alarming one.
Why Small Thin Women Are Particularly Affected
DEXA measures areal bone mineral density, meaning it calculates density based on the two-dimensional area of the bone as seen on the scan. Smaller bones have a smaller projected area, which produces a lower density reading even when the bone is proportionally just as strong. A woman who is petite and light will consistently score lower on DEXA than a larger woman with identical bone quality and fracture risk.
This is not a theoretical concern. It results in real women being told they have severe osteoporosis, being placed on medications with significant side effects, and living with anxiety about their bone health, when their actual fracture risk does not justify any of it. The woman whose orthopedic surgeon husband watched her fall on ice without breaking anything is one example. She is not alone. In my practice, I see petite perimenopausal and postmenopausal women regularly who carry alarming DEXA results that do not match their clinical presentation.
For the perimenopausal woman in particular, this matters because she is already navigating a significant hormonal transition with real implications for her mood, sleep, cognition, and metabolic health. Adding a frightening bone diagnosis on top of that, especially one that may not accurately reflect her fracture risk, creates fear that drives treatment decisions that may carry more risk than the condition they are treating.
The Hormonal Drivers of Bone Loss That DEXA Cannot See
A DEXA result is a snapshot of bone density at one point in time. It tells you nothing about the rate of change, the direction of change, or the underlying drivers of whatever it is measuring. This is one of the most important limitations of relying on DEXA alone for bone health management in perimenopausal and menopausal women.
In my practice, I always look at bone health in the context of the full hormonal picture. Estradiol and progesterone levels, the ratio between them, and the trajectory of that ratio over time all influence bone turnover in ways that a T-score cannot capture. A woman in early perimenopause with normal estrogen but declining progesterone may already be losing ground on the bone-building side. Her DEXA may look fine. Her clinical picture may tell a different story.
Insulin resistance is another underappreciated driver of bone health. Advanced glycation end products, which accumulate in the presence of chronically elevated blood sugar, degrade collagen crosslinks in bone and reduce bone toughness independent of density. This means a woman with insulin resistance or pre-diabetes can have bones that are more brittle and more prone to fracture than her T-score suggests. DEXA will not show you this. A complete metabolic picture will.
Vitamin D insufficiency is nearly universal in women over 45, particularly in the Bay Area where sun avoidance is common. Vitamin D is essential for calcium absorption and bone mineralization. Low vitamin D does not just affect bone density. It affects the quality of the bone matrix, the framework within which mineral is deposited. A woman with low vitamin D can have bones that are less structurally sound than their density reading implies.
Inflammation is the final piece most doctors are not looking at. Chronic low-grade inflammation, which is extremely common in perimenopausal women with blood sugar dysregulation, gut dysfunction, or unresolved infections, upregulates inflammatory cytokines that directly stimulate osteoclast activity. In simple terms, chronic inflammation accelerates bone breakdown. A woman with significant inflammatory burden is losing bone faster than her hormonal status alone would predict, and no bone scan on its own will tell you why.
What REMS Measures That DEXA Cannot
REMS, which stands for Radiofrequency Echographic Multi-Spectrometry, is an ultrasound-based technology that analyzes the raw, unfiltered signal produced when sound waves move through bone. It does not use radiation. It examines the same sites as DEXA, the lumbar spine and proximal femur, and produces both a T-score and something DEXA cannot generate: the Fragility Score.
The Fragility Score runs from 0 to 100. Lower is better. It is calculated by comparing the patient's bone signal to reference models built from both fractured and non-fractured subjects, and it reflects the internal architecture of the bone, the microstructural organization that determines how well bone absorbs and distributes force. This is what actually protects you when you fall. And it is completely independent of your body size.
That is why the orthopedic surgeon's wife scored low on the Fragility Score despite a severe T-score. Her bone architecture was sound. Her density reading was skewed by her small frame. REMS could see past the size. DEXA could not.
REMS also does not penalize small body size. Because it analyzes the quality of the acoustic signal from the bone rather than measuring a projected area, it is far less influenced by how much a woman weighs or how tall she is. For petite women, many of whom are also the ones most likely to be told they have osteoporosis based on DEXA, this distinction can be the difference between an accurate result and a medically unnecessary diagnosis.
For perimenopausal and menopausal women specifically, REMS offers something else that DEXA does not: the ability to track changes in bone quality over time, not just density. Because the Fragility Score reflects the structural integrity of bone, it can detect early deterioration in bone quality even when density has not yet changed significantly. For women in the early perimenopausal years, this is a meaningful clinical advantage.
The Fragility Score in Practice
On the Fragility Score scale, a score between 0 and 20 indicates strong, healthy bone with low fracture risk. Between 21 and 40 is moderate, with some early signs worth monitoring. Between 41 and 60 indicates meaningful bone weakening with higher fracture risk. Above 60 warrants prompt clinical attention.
The score is generated independently of bone mineral density, which means it can show strong bones in a woman with a poor T-score, or concerning bone quality in a woman whose T-score looks acceptable. For clinical decision-making around whether a patient actually needs osteoporosis medication, this distinction is significant. Bisphosphonates and other osteoporosis drugs are not without risk. Osteonecrosis of the jaw and atypical femur fractures are documented consequences of long-term use. Getting the diagnosis right before beginning treatment is not a small matter.
Where the Two Tests Agree and Where They Diverge
For most women of average height and weight, DEXA and REMS produce broadly similar conclusions. When a woman has genuinely low bone density and poor bone quality, both tests will reflect that. The divergence happens at the edges: small thin women who score poorly on DEXA but have good bone quality on REMS, and occasionally the reverse, women whose DEXA looks acceptable but whose Fragility Score reveals bone quality that deserves more attention.
In my experience, the reverse situation, a reassuring DEXA with a concerning Fragility Score, is particularly common in women with significant inflammatory burden, insulin resistance, or long-standing nutrient deficiencies. Their bones may be mineralizing adequately but structurally degrading in ways that density measurement cannot detect. This is exactly the kind of clinical pattern that gets missed when the workup stops at DEXA.
What a Complete Bone Health Assessment Actually Looks Like
A REMS scan, or any bone scan, is one piece of a complete bone health picture. For a full workup, the scan result needs to be read alongside estradiol and progesterone levels and their trajectory, thyroid function, fasting insulin and blood sugar markers, vitamin D status, omega-3 levels, inflammatory markers including homocysteine and fibrinogen, and a complete metabolic panel.
Bone health is downstream of all of these systems. You cannot optimize bone health by treating a T-score in isolation any more than you can optimize hormone health by treating a single lab value in isolation. The systems are interconnected. The treatment approach has to reflect that.
This is the clinical framework I bring to every bone health conversation in my practice. And it is why I have been wanting to add REMS for some time. A tool that measures bone quality independently of density, without radiation, and without penalizing small body size fits directly into how I already approach bone health as one piece of a complete clinical picture.
REMS Is Coming to Wellness Architecture This September
REMS bone assessments are coming to Wellness Architecture this September. Dates and availability will be announced in August. Spaces will be limited and will go to the Early Access List first. If you already know you want this done, sign up now.
If you want to talk through whether REMS is the right next step for you, schedule a Discovery Call.
Frequently Asked Questions
Is REMS a replacement for DEXA?
Not necessarily a replacement, but a meaningful complement and in some cases a more accurate picture. DEXA remains the clinical standard for formal osteoporosis diagnosis. REMS adds bone quality information that DEXA cannot provide, and is particularly valuable for women whose DEXA results may be skewed by small body size, or who want a radiation-free option for monitoring bone health over time through the menopausal transition.
When is the best time for a perimenopausal woman to get a bone assessment?
Earlier than most conventional doctors recommend. By the time significant bone loss shows up on a DEXA, it has usually been occurring for several years. I prefer to establish a baseline picture in the early perimenopausal years, ideally in the mid-40s, so we know the starting point and can monitor the trajectory rather than reacting to a number after the fact. A REMS assessment alongside a complete hormonal and metabolic panel gives the clearest early picture.
Who benefits most from REMS over DEXA?
Women who are petite or light and have received an alarming DEXA result. Women diagnosed with osteoporosis whose clinical picture does not seem to match. Women who have fractured despite normal or near-normal DEXA results. Women with significant inflammatory burden, insulin resistance, or metabolic dysfunction who want a bone quality assessment that reflects more than density. And women who want a radiation-free option for ongoing monitoring.
What is the Fragility Score and how is it different from a T-score?
A T-score compares your bone mineral density to a healthy young adult reference population. It tells you about density. The Fragility Score is unique to REMS and measures bone quality independent of density, by comparing your bone's acoustic profile to reference models from both fractured and non-fractured subjects. Lower is better. A low Fragility Score means strong bone quality and low fracture risk regardless of what the T-score shows.
Does REMS use radiation?
No. REMS uses ultrasound. This makes it safe for more frequent monitoring and appropriate for women who want to avoid repeated radiation exposure, including younger perimenopausal women who may need serial assessments over many years.
How do hormones affect bone health specifically?
Estrogen suppresses osteoclast activity, meaning it slows bone breakdown. When estrogen declines in perimenopause and menopause, bone resorption accelerates. Progesterone stimulates osteoblast activity, the bone-building side, and its decline in early perimenopause can shift the balance toward net bone loss even before estrogen drops significantly. Cortisol inhibits osteoblast function directly. Thyroid dysfunction, particularly subclinical hyperthyroidism, increases bone turnover independently of sex hormones. All of these need to be part of the bone health conversation, not just the T-score.
Will my doctor accept REMS results?
Acceptance varies. DEXA remains the standard most physicians and insurance systems recognize for formal diagnosis and treatment decisions. REMS results provide important context and can prompt a more thorough clinical conversation. We will go through your results together and help you understand what they mean in the full context of your bone health, hormonal status, and metabolic picture.
For more on what a complete clinical picture looks like, read: She Suffered for Decades. Her Symptoms Told Me Everything Before the Labs Even Came Back.
Related reading:
- What a Complete Lab Panel Reveals That 30 Years of Doctor Visits Missed
- Why Hormone Replacement Alone Is Not Enough
- Why Stress Hits Women Over 45 Completely Differently
- Perimenopause Symptoms That Are Ruining Your Sleep, Mood, and Energy
For the source on fracture risk and the evolving role of bone mineral density, see the 2025 International Osteoporosis Foundation Position Paper published in Osteoporosis International.