The Long-Term Complications of Type 2 Diabetes (And How to Lower Your Risk)

Why Complications Happen in Type 2 Diabetes

Type 2 diabetes usually doesn’t appear overnight. It often starts years earlier with insulin resistance. Insulin is like a key that unlocks tiny “doors” on your cells, allowing glucose to move out of your bloodstream and into your muscles and organs for energy. As insulin resistance develops, those doors stop responding well to insulin. The key still knocks–but the door barely opens.

When that happens, more and more glucose starts building up in your blood instead of getting inside the cells. At first, this may show up as prediabetes: an A1C between 5.7–6.4% or a fasting blood sugar between 100–125 mg/dL. If nothing changes, it can progress to type 2 diabetes, defined as an A1C of 6.5% or higher or fasting glucose of 126 mg/dL or above on repeat testing.[1]

Over months and years, that extra glucose doesn’t just “float around” harmlessly. High blood sugar is actually toxic to delicate blood vessels and nerves. It irritates the lining of arteries, damages tiny capillaries, and stresses organs like the heart and kidneys. This is how long-term complications begin.

Major Long-Term Complications to Be Aware Of

Heart Disease

Cardiovascular disease–heart attacks, strokes, and heart failure–is the number one cause of death in people living with diabetes. People with type 2 diabetes are more likely to develop and die from heart disease than people without diabetes.[2] This happens because high blood sugar, high blood pressure, and unhealthy cholesterol all damage the arteries over time.

The good news is that when blood sugar, blood pressure, and cholesterol are well controlled, and when you’re more active and eating a heart-healthy diet, your risk can drop significantly.[2]

Kidney Disease

Your kidneys act like filters for the blood, removing waste and excess fluid. When glucose stays high for years, it damages the small blood vessels inside the kidneys. Over time, this reduces their ability to filter properly and can lead to chronic kidney disease or even kidney failure.

Chronic kidney disease occurs in roughly 20–40% of people with diabetes and is a major reason many patients end up needing dialysis or a transplant.[3,4] Diabetes is now one of the leading causes of kidney failure in the United States.[4] This is why your doctor checks your urine and kidney labs regularly–these tests are early warning signs that help catch kidney problems before they become severe.

Nerve Damage and Foot Problems

Nerves carry messages between your brain and the rest of your body. High blood sugar can damage these nerves (a complication called diabetic neuropathy) as well as the small blood vessels that supply them.[4] Many people notice this first in their feet as numbness, tingling, burning, or pain.

Neuropathy matters not only because it hurts, but because numbness makes it easy to miss cuts, blisters, or sores on your feet. When blood flow to the feet is reduced, wounds can heal very slowly and are more likely to become infected. In serious cases, this can lead to ulcers and, eventually, amputations.[4] This is one reason diabetes is a leading cause of non-traumatic lower-limb amputations.

Checking your feet daily, keeping them clean and moisturized (but not between the toes), and seeing a podiatrist regularly are simple but powerful ways to lower your risk.

Eye Disease and Vision Loss

Your eyes are full of tiny, delicate blood vessels–especially in the retina, the light-sensitive layer at the back of the eye. High blood sugar can damage these vessels and cause them to swell or leak, a condition called diabetic retinopathy.[4,5]

Diabetic retinopathy is one of the leading causes of vision loss and blindness in working-age adults worldwide.[5] Early on, you may not notice symptoms at all. That’s why yearly dilated eye exams are so important when you have diabetes. Catching changes early allows treatments (like lasers or injections) to protect your vision.

How Better Blood Sugar Protects You

Here’s the hopeful part: lowering your A1C and fasting blood sugar doesn’t just “look better” on your lab report. It changes your future risk of complications in a real way.

Large clinical trials in people with diabetes have shown a clear relationship between A1C and microvascular complications–retinopathy (eye disease), nephropathy (kidney disease), and neuropathy (nerve damage). Keeping A1C around or below 7% has been shown to reduce the risk and slow the progression of these problems.[6] The exact target should always be personalized with your healthcare team, but aiming for safer ranges matters.

Think of every 0.5–1.0% drop in A1C as moving your body away from damage and closer to healing. It’s not about being “perfect.” It’s about steady progress that your organs will thank you for years from now.

Lifestyle Steps to Lower Your Risk (Alongside Medication)

Medications prescribed by your doctor–like metformin, GLP-1 receptor agonists, SGLT2 inhibitors, or insulin–play a crucial role in protecting you from complications. They’re not a sign of failure; they’re tools to keep blood sugar levels out of the dangerous zone while you work on lifestyle changes.

At the same time, lifestyle shifts make a huge difference:

1. Choose a sustainable eating pattern.

Different diets can work, but research consistently supports Mediterranean-style and plant-forward patterns for people with type 2 diabetes. These approaches focus on vegetables, fruits, whole grains, beans, lentils, nuts, seeds, and healthy fats like olive oil, while limiting red and processed meats, refined grains, and sugary foods.[7-9] Studies show these patterns can improve A1C, support weight loss, and reduce heart disease risk in people living with diabetes.[7-9]

2. Move your body regularly.

Physical activity makes your cells more sensitive to insulin. Aim to walk most days of the week–especially after meals. Even a 15-20 minute walk after your biggest meal can help lower your post-meal glucose. Adding 2-3 days of resistance or strength training (using weights, machines, or resistance bands) helps build muscle, which acts like a sponge for blood sugar.

3. Keep up with check-ups and screenings.

Regular visits with your healthcare team, lab work, eye exams, kidney tests, and foot exams are all part of preventing long-term damage. These appointments catch small issues early—when they are easier to treat.

You’re Not Helpless–You’re in the Driver’s Seat

Hearing about heart disease, kidney failure, nerve damage, or vision loss can feel heavy. But remember: these complications usually arise when type 2 diabetes is left untreated or poorly controlled for many years. They are not your guaranteed future.

By taking your medications as prescribed, choosing a way of eating you can live with, walking after meals, building strength, and staying on top of your medical care, you’re stacking the odds in your favor. Every better choice you make today is a gift to your future self–the one who wants to travel, play with grandkids, stay independent, and enjoy life without being held back by diabetes.

You deserve that future, and you can start moving toward it one small, steady step at a time.

References

[1] Centers for Disease Control and Prevention. “Diabetes Testing.” 2024. (CDC)

[2] American Heart Association & American Diabetes Association. “Cardiovascular Disease and Diabetes.” 2024. (www.heart.org)

[3] Lu X, et al. “Type 2 diabetes mellitus in adults: pathogenesis, management and future perspectives.” Signal Transduct Target Ther. 2024. (Nature)

[4] Medscape. “Type 2 Diabetes Mellitus: Complications.” Updated 2025. (Medscape Reference)

[5] Zakir M, et al. “Cardiovascular Complications of Diabetes.” Cureus. 2023. (PMC)

[6] American Diabetes Association. “Glycemic Goals and Hypoglycemia: Standards of Care in Diabetes—2024.” and analyses of DCCT/UKPDS and related trials. (Diabetes Journals)

[7] Milenković T, et al. “Mediterranean Diet and Type 2 Diabetes Mellitus.” Nutrients. 2021. (MDPI)

[8] Esposito K, et al. “Mediterranean diet and type 2 diabetes.” Endocrine. 2014. (PubMed)

[9] Qian F, et al. “Association Between Plant-Based Dietary Patterns and Risk of Type 2 Diabetes.” JAMA Intern Med. 2019; and Marsh K. “Plant-based diets and type 2 diabetes.” Australian Diabetes Educators Association, 2024. (JAMA Network)