Type 2 diabetes affects 37 million Americans. Here is what you need to know.

YOUR HEALTH — Issue No. 29

More than 37 million Americans have type 2 diabetes. Another 96 million have prediabetes — meaning their blood sugar is elevated, but has not crossed the threshold into diabetes yet. Those numbers are staggering, and they reflect something I see every single day in practice. This is one of the most common diagnoses I make, and one of the most consequential. If you read Issue #28 on prediabetes, type 2 diabetes is where that process has advanced further.

When I sit down with a patient who has just been diagnosed, I usually tell them one of two things is happening. Either the body is not producing enough insulin, or what it is producing, the body is not responding to properly. In the overwhelming majority of cases, it is the second one — insulin resistance, not insulin deficiency. The pancreas is doing its job. The cells throughout the body have simply stopped listening. The exception I watch for is a patient who has had uncontrolled blood sugar for years, or someone who is not overweight and is not responding to treatment the way I would expect. In those cases, I start thinking about beta cell exhaustion — the insulin-producing cells in the pancreas that can wear out over time from years of overwork. That changes how I approach treatment. But for most patients sitting across from me at diagnosis, the problem is resistance, and that is where we start.

What I want patients to understand is that this diagnosis feels manageable right up until it is not. The complications develop quietly, over years, without symptoms. By the time something hurts, or something stops working the way it should, the disease has often been doing damage for a long time.

The case for treating it aggressively from the start

Every year spent with elevated blood sugar adds to a patient’s cumulative exposure. Getting blood sugar under control early reduces that exposure, and lowers the risk of complications over time. A controlled A1c at year one is not the same as a controlled A1c at year ten — and the difference shows up in the kidneys, the eyes, and the nerves.

The evidence for this is compelling. Research has shown that patients who achieved good blood sugar control early in their diagnosis carried lasting protection against complications — even years later. The body, in a sense, remembers early good control. That window matters, and it is worth using.

Lifestyle is not a footnote in this conversation. What a patient eats, how much they move, whether they sleep — all of it matters alongside medication. Not because medication does not work, but because the two together work considerably better than either one alone.

The three complications I watch for most closely

Kidney disease. The kidneys filter blood continuously, and chronically elevated blood sugar damages the small vessels that make that filtration possible. I check a urine albumin-to-creatinine ratio — a UACR — at least once a year in every patient with type 2 diabetes. It measures whether protein is leaking into the urine, which is one of the earliest signs of kidney involvement. I also follow the eGFR, which reflects how well the kidneys are actually functioning. Together, these two numbers tell me a great deal about where things stand. Finding this early changes the outcome — the options for slowing progression are considerably better when kidney involvement is caught before symptoms appear.

Eye disease. Diabetic retinopathy is a leading cause of blindness in working-age adults in the United States, and it produces no symptoms in its early stages. By the time vision changes appear, disease has often progressed significantly. This is why I tell every patient with type 2 diabetes: you need a dilated eye exam. A trained ophthalmologist looking directly at the retina can detect changes years before you notice anything wrong.

Nerve damage. Neuropathy typically starts in the feet — numbness, tingling, a sensation of walking on sand. Because sensation is reduced, injuries go unnoticed. Because they go unnoticed, they escalate. I ask patients to look at their feet regularly — not a glance, but a real look. New calluses. Blisters in unusual places. Redness or warmth that does not resolve. These need to come to a provider’s attention before they become something worse. Your provider should also examine your feet at least once a year to check sensation, circulation, and areas at risk for ulcers.

The treatment landscape is genuinely different now

When I started in practice, the medication options were more limited, and insulin often entered the conversation sooner. That has changed significantly. There are now medications that lower blood sugar while also protecting the heart, protecting the kidneys, and for some patients, supporting meaningful weight loss.

Metformin remains a common, inexpensive, well-studied option. It works on insulin resistance — the underlying mechanism driving most of the disease — and it is an appropriate starting point for many patients.

SGLT2 inhibitors — medications like empagliflozin and dapagliflozin — help the kidneys remove glucose through the urine. For patients with kidney disease or heart failure, these medications provide important protection that goes well beyond blood sugar control. That is why I reach for them early in patients who need that layer of coverage.

GLP-1 receptor agonists and related medications — including Ozempic and Mounjaro — have changed what is possible for many patients. They lower blood sugar, reduce appetite, and support weight loss. Some have demonstrated cardiovascular and kidney benefits in specific patient populations. For patients whose diabetes is closely tied to excess body weight, these medications can address an important contributor to insulin resistance.

I rarely have to put a patient with type 2 diabetes on insulin today. That is not because insulin is not a good medication — it is — but because we have so many effective options before we get there.

One more tool I want every patient with type 2 diabetes to know about: continuous glucose monitors, or CGMs. Devices like the Freestyle Libre and the Dexcom give you a real-time picture of your blood sugar throughout the day — not just a single snapshot at a lab draw, but a continuous read of how your body responds to food, activity, stress, and medication. I am a strong advocate for these devices because they turn an abstract number into something patients can actually see and learn from. A patient who watches their blood sugar spike after a bowl of white rice and stay flat after a walk understands their disease in a way that a quarterly A1c never quite captures.

If you have type 2 diabetes, ask your provider whether a CGM is right for you. Many insurance plans — including Medicare — cover them. If you are not sure whether you are covered, a call to your insurance company or a conversation with your provider is worth the effort. Ask them to send in a prescription. It is one of the most practical things you can do to understand what is happening in your own body.

Diabetes is a progressive disease. Treatment that works well today may need to be adjusted as time goes on. The goal is not to find a plan and stay with it forever — it is to stay ahead of where the disease is going.

Something worth saying plainly:

Unmanaged type 2 diabetes does not just affect blood sugar. Adults with type 2 diabetes have roughly twice the risk of heart disease and stroke compared to people without it. The risk of dementia is also substantially elevated — research consistently shows that diabetes approximately doubles the risk of developing it. These are not rare outcomes. They are the downstream consequences of years of elevated blood sugar left unaddressed.

The good news is that this disease responds to management. The monitoring, the medication, the lifestyle work — it all adds up. The patients I have seen do best with this diagnosis are the ones who understood early that staying ahead of it was worth the effort.

If you have not checked your diabetes risk — or you know someone who should — the Plain Diabetes Check is a free tool at tools.plainmedicine.health/diabetes. Seven questions. About 60 seconds. It gives you a plain-language picture of where you stand.

Next week: Chronic Kidney Disease — what happens when the kidneys are under sustained pressure, what the numbers mean, and why catching it early changes everything.

The paid deep-dive this week covers diabetic kidney disease, eye disease, and neuropathy in clinical depth — what the monitoring tests actually mean, what treatment looks like when complications develop, and the question I hear most often from patients with a controlled A1c.

Plain Medicine is published for educational purposes only and does not constitute medical advice or establish a patient-provider relationship. Always consult your healthcare provider before making medical decisions.

— Kyle