How Diabetes Affects Your Kidneys (And What You Can Do About It)

Your kidneys do a lot of quiet, unglamorous work. Every day, they filter about 200 quarts of blood, removing waste, balancing fluids, and keeping your body running smoothly. For people living with health concerns involving diabetes and kidneys, that quiet work can slowly become compromised—often without a single noticeable symptom. But how does diabetes affect the kidneys?

Understanding the connection between diabetes and kidneys is one of the most important things you can do for your long-term health. This post breaks it down clearly, so you know what to watch for, how to slow things down, and when it’s time to bring in a kidney specialist.

What Does Diabetes Do to Your Kidneys?

Your kidneys filter blood through millions of tiny blood vessels called nephrons. When blood sugar stays consistently high over time, it gradually damages those small vessels, making it harder for your kidneys to do their job properly. Waste that should be removed starts building up in the blood, and the kidneys may also begin leaking protein into the urine—a sign that something’s wrong.

This gradual process is often known as diabetic kidney disease, or diabetic nephropathy. Both type 1 and type 2 diabetes can lead to it. The longer someone has had diabetes—and the less controlled their blood sugar has been—the higher their risk. So does diabetes affect the kidneys across both types? Yes, though the timeline and risk factors can vary.

Signs Your Kidneys May Be Affected

Here’s where it gets tricky. Early-stage kidney damage often has no symptoms at all. That’s not a reason to relax—it’s a reason to test regularly.

As damage progresses, some people notice:

• Swelling in the legs, ankles, or feet
• Fatigue or difficulty concentrating
• Changes in urination, such as foamy urine, or going more or less often than usual
• Difficulty managing blood pressure, even with medication

Because these signs can appear late—or not at all—routine testing for diabetes and kidneys matters far more than waiting to see these warning signs.

How Do Doctors Check for Kidney Damage from Diabetes?

Two tests are used most often. A urine albumin test checks for protein in the urine, which is one of the earliest detectable signs of kidney stress. A blood creatinine test measures how well your kidneys are filtering waste—this is used to calculate your eGFR (estimated glomerular filtration rate), which tells you what stage of kidney function you’re at.

According to the National Kidney Foundation, people with diabetes should have both tests done at least once a year.

What Can You Do to Support Your Kidney Health?

The good news: there’s a lot within your control. Here are some things you can do to actually reduce your health risk regarding diabetes and kidneys.

• Manage your blood sugar. Keeping A1C in your target range is the single biggest thing you can do to slow kidney damage from diabetes.
• Keep blood pressure under control. High blood pressure and kidney disease fuel each other. Aim for below 130/80 mmHg, or as recommended by your doctor.
• Ask about your medications. Some drug classes have been shown to offer kidney-protective benefits in people with diabetes. Talk to your doctor about whether they’re right for you.
• Eat with both conditions in mind. A kidney-supportive diet typically limits sodium, processed foods, and excess protein. A dietitian familiar with diabetes and kidneys can help you build a practical plan to support both blood sugar and kidney health.
• Move regularly. Even moderate physical activity helps manage blood sugar and blood pressure. Find something sustainable, not punishing.
• Avoid smoking. Smoking speeds up kidney damage and increases cardiovascular risk—both serious concerns when managing how diabetes affects the kidneys long-term.
• Watch what you take over the counter. NSAIDs like ibuprofen can strain the kidneys. Certain supplements can too. Always check with your care team before adding anything new.
• Show up to your appointments. This sounds basic, but staying on top of your lab results is how you catch changes early—before they become harder to manage.

When Should You See a Nephrologist?

Your primary care doctor or endocrinologist may manage early concerns regarding diabetes and kidneys, but there are situations where a nephrologist—a kidney specialist—is worth bringing in sooner. Consider a referral if:

• Your eGFR is below 45 or dropping steadily
• You have protein in your urine that isn’t responding to treatment
• Your blood pressure is hard to control despite medication
• You want a specialist to help coordinate care as diabetes and kidneys become more complex to manage together

Getting ahead of things is always better than catching up.

Frequently Asked Questions

How does diabetes affect the kidneys, and can it really cause damage?

Yes. High blood sugar injures the small blood vessels inside the kidneys, reducing their ability to filter waste effectively. Over time, this can lead to diabetic kidney disease—one of the leading causes of kidney failure in the United States.

What are the early signs of diabetic kidney disease?

Early-stage diabetic kidney disease usually has no symptoms. The first detectable sign is typically protein in the urine (albuminuria), which is found through routine lab testing—not by how you feel.

How often should someone with diabetes get their kidneys checked?

At least once a year. The National Kidney Foundation recommends annual urine albumin and blood creatinine tests for anyone with diabetes, regardless of how well-controlled their condition is.

Can diabetic kidney disease be prevented?

In many cases, yes—or at least significantly delayed. Tight blood sugar control, managed blood pressure, a kidney-supportive diet, regular physical activity, and avoiding nephrotoxic substances can all meaningfully reduce risk.

Can diabetic kidney disease be reversed?

Early stages may be slowed or partially improved with the right interventions. However, kidney damage that has progressed significantly is generally not reversible. This is why early detection and consistent management matter so much.

Talk to the Team at Texas Kidney Institute

If you have diabetes and want to understand where your kidney health stands—or if you’ve already been told something’s going on—Texas Kidney Institute is here to help. With over 20 locations across the Dallas area and a team of experienced nephrologists, Texas Kidney Institute offers the kind of personalized, specialist-level care that makes a real difference over time.

Schedule an appointment today to learn more about your health regarding diabetes and kidneys.