When Data Helps and When It Hurts: A Doctor's Take on Labs, CGMs, and Wearables
As a primary care and obesity medicine physician, I love data and tracking. Be it weight or blood pressure monitoring or continuous glucose monitoring, it is wonderful to be able to see the numbers, create interventions, and validate them. I've watched continuous glucose monitors change lives—not just for people with diabetes, but for prediabetic patients who, for the first time, can see how a particular meal or stressful afternoon affects their blood sugar in real time. This is powerful feedback.
But after twenty years of practice, I'm also watching something else: data is becoming a stressor in itself. Patients arrive with screenshots of trackers, lists of supplements and labs that social media or AI recommended, and a low hum of anxiety underneath it all. Am I doing enough? Are my numbers good? What does this one slightly off result mean?
So here is what your labs and your wearables can—and can't—tell you, from a doctor who uses them every day and watches how sometimes the usage backfires.
What Data Is Actually For
Numbers tell a story over time. That's the most important thing to understand about labs and tracking: a single value rarely means much. A trend across months or years does.
Most chronic illnesses—high blood pressure, type 2 diabetes, high cholesterol, thyroid disease—develop slowly and quietly. Patients are often genuinely surprised to wake up one day with a diagnosis, because their symptoms have been so slow and so quiet. The job of regular labs and consistent tracking is to make those slow changes visible early, while there's still time to change the trajectory.
This is where data is helpful. A CGM showing a prediabetic patient how a certain breakfast spikes their sugar. A blood pressure trend that quietly drifts upward over two years. A cholesterol pattern that reveals itself only when you have the last four years' results side by side. Used this way, data isn't anxiety-inducing—it's a partnership tool between you and your doctor.
Why Blanket Recommendations Don't Work
Online health information tends to be confident, simple, and one-size-fits-all: Drink more water. Eat more protein. Get more fiber. Take this supplement. It sounds clean, but it doesn't match how actual bodies work.
A patient with kidney disease shouldn't load up on protein—it can accelerate kidney damage.
A patient with gout can precipitate a flare with the same high-protein advice that helps someone else lose weight.
A high-fiber diet that helps one person feel great can cause uncomfortable bloating in another.
A patient on fluid restriction for heart failure can be genuinely harmed by "hydrating all day."
Even something as simple as "increase your protein" needs context. I've seen patients become constipated from raising protein too quickly without enough fiber, water, and movement to match.
This is why I'm always wary of advice that treats every body the same. Your plan has to fit you—your conditions, your medications, your stage of life, your goals, and what you can actually sustain. We are not clones; we are unique beings with our own blueprints, and any tweaking has to be personalized.
When Data Starts to Hurt
Tracking is wonderful until it isn't. I've seen this play out in too many ways to ignore.
One pattern I see often: patients with diabetes wearing a CGM wake up at 4 a.m. because their device alerts them to a sugar reading that's slightly low—but they have no symptoms of hypoglycemia. Frightened by the number, they eat something. Their morning glucose then spikes well above target, and the rest of the day's blood-sugar control suffers because of one alert that perhaps didn't need a response. The device was meant to give them information; it ended up ruining not only their night, but the day as well.
I see the same dynamic with patients who fixate on tiny lab variations. An MCHC or BUN that's 0.1 off. A cholesterol number that bounces a few points. These matter very little in isolation. But once they're seen, they're hard to unsee—and patients begin a cycle of more testing and more anxiety, mostly because they have symptoms that deserve to be evaluated by a trusted clinician.
Then there are the direct-to-consumer labs that have become common. Many of them order tests with little clinical context, no interpretation, and no one to help you make sense of what comes back. Patients arrive in my office with a stack of results and one question: What do I do with all this? Often the honest answer is: not much. It hurts me to see patients out hundreds of dollars searching for answers in tests that frequently aren't clinically relevant or well-supported by evidence.
What I Watch For With My Patients
When I look at a patient's data—labs, blood pressure readings, CGMs, wearables, weight trends—I'm asking a few questions:
What is the trend, and how does it compare to the past?
Is this number changing in a way that matters clinically? What change of management would this prompt?
Does the number match the symptoms, or is there a gap between how the patient feels and what the data shows?
What would I actually do differently because of this result?
How does the patient feel about a proposed change, and is it realistic for this person? (A shift worker can't be told to wake up and exercise for 30 minutes in the morning. A long-haul truck driver can't be held to a regimented home-cooked meal plan.)
That last question is often the most important. A test or a tracker is only useful if it changes a decision. If a result doesn't move the plan in any direction, ordering it usually just adds noise—and often anxiety, which can be as damaging to a person as the disease itself.
Normal labs also do not mean a patient's symptoms should be dismissed. The number on the page is one piece of information; how a person feels is another. A good doctor weighs both.
A Story From My Own Walk
I take a post-dinner walk most days. It's my me-time, and I love closing the rings on my watch at the end of the day—it makes me feel like I accomplished something.
One evening, my watch was out of charge and it was getting dark outside. I couldn't wait for it to charge. I caught myself in a moment of real conflict: I almost didn't want to go on the walk, because if it wasn't measured, it somehow felt like it wouldn't count.
How crazy is that?
I had to remind myself: my father walked. My grandfather walked. Neither of them counted steps. They moved as part of their day, and they didn't need a screen to validate the movement. Even I didn't have any of these devices until a few years ago.
I love the tracking. I love seeing my progress. But that small moment showed me how easily even a physician can become tethered to the data instead of the doing. And when I see it in my own patients, I want to gently free them from it too.
Listening to Your Body Is Still the Best Skill
Babies and pets do something most adults have forgotten how to do: they move and play until they're tired, they eat when they're hungry, they rest when they need to. They trust their own internal signals.
Somewhere along the way, most of us lost touch with that. We measure instead of feel. We chase numbers instead of noticing the body underneath them.
But there is a middle path. Use the data. Get your labs. Wear the tracker if it helps you. But also: take a walk once in a while just for the walk. Eat until you're about three-quarters full. Drink water when you're thirsty. Sleep well. Make time for the things that calm you—prayer, meditation, journaling, your hobbies, whatever quiets the noise.
Get your labs and your screenings on schedule, and have a doctor who knows you well enough to tell you what actually matters and what doesn't. That partnership is what turns data from a stressor into a tool—and lets you live the life all the tracking is supposed to be supporting in the first place.
If you're sorting through labs, trackers, or just trying to figure out what's actually worth paying attention to, I'd be glad to help. Schedule a Meet & Greet to learn more about Anchor Primary Care.
