DIABETES COMPLICATIONS & LONG-TERM HEALTH

Diabetes and Kidney Health: Protecting Your Internal Filters

How high blood sugar strains microscopic kidney filters, why early changes are silent, and how simple annual lab tests catch changes early.

4 min readMay 19, 2026

Medical graphic illustrating kidney filtering blood vessels — Photo via Monoar_CGI_Artist / Pixabay (opens in a new tab)

Your kidneys are two bean-shaped organs that act as your body's master filtration system. Inside each kidney, about one million microscopic units called nephrons filter waste products and extra fluid from your blood into urine, while holding onto vital proteins, according to the NIDDK (opens in a new tab).

Because these filtering nephrons are packed with delicate microscopic blood vessels, long-term unmanaged blood sugar and high blood pressure can strain them over time. Diabetes is the leading cause of kidney disease worldwide, and roughly one in three adults with diabetes has some degree of it — but the NIDDK (opens in a new tab) is clear that this damage typically develops slowly over many years, which leaves a wide window for screening and treatment to change the outcome.

What Is Diabetic Kidney Disease (Nephropathy)?

Diabetic kidney disease develops gradually when high glucose causes the kidney's filtering units to work extra hard, a state called hyperfiltration. Over months and years, the pressure inside each nephron's filter (the glomerulus) can thicken and stiffen its walls. As the filter membrane changes shape, the microscopic pores that are meant to hold back protein become slightly less selective, allowing tiny amounts of a vital blood protein called albumin to leak into the urine. This is the first measurable sign of kidney strain, long before someone would notice anything is different.

Early stage (moderately increased albuminuria): Small amounts of protein leak into urine. There are zero physical symptoms or pain, and kidney filtration itself is often still normal or even slightly above normal.
Intermediate stage (severely increased albuminuria): Protein leakage increases further, blood pressure often rises, and filtration (eGFR) may begin trending downward.
Advanced stage (declining eGFR / reduced kidney function): Filtration efficiency drops meaningfully, which can eventually lead to fluid retention (swelling in ankles and feet), fatigue, and changes in appetite as waste products build up.

Early Kidney Changes Can Often Be Stopped or Reversed

Catching kidney strain at the early, moderately-increased-albuminuria stage is genuinely good news. With blood sugar and blood pressure brought into target range, plus protective medications when prescribed — ACE inhibitors or ARBs, and SGLT2 inhibitors such as dapagliflozin or empagliflozin — early protein leakage can often be reduced or reversed. This is the single strongest reason not to skip the annual urine test even when you feel completely well.

The Two Essential Kidney Tests, and How Often to Repeat Them

Because early kidney strain is completely silent, screening does not rely on symptoms at all. The ADA's Standards of Care (opens in a new tab) recommends two simple lab tests, done together at least once a year:

1Urine Albumin-to-Creatinine Ratio (UACR): A simple spot urine sample that measures how much albumin is leaking relative to creatinine, catching microscopic protein loss long before it would show up on a basic urine dipstick.
2Serum Creatinine, used to calculate eGFR (estimated Glomerular Filtration Rate): A standard blood sample that estimates how effectively your kidneys are clearing waste from your blood, expressed as a percentage of normal filtering capacity.

Situation	Recommended testing interval
Type 2 diabetes	UACR and eGFR at least once a year, starting from diagnosis
Type 1 diabetes	UACR and eGFR at least once a year, starting 5 years after diagnosis
Albuminuria or reduced eGFR already found	Typically increased to twice a year or more, guided by your care team

These two numbers are read together, not in isolation — a normal eGFR with rising UACR, or a normal UACR with declining eGFR, both matter and can prompt a treatment change well before either reaches an advanced stage.

What Protects Kidney Function Alongside Screening

Blood sugar in your target range most of the time, which directly reduces the hyperfiltration pressure inside each nephron.
Blood pressure control — kidney filters are made of blood vessels, so the same pressure that strains the heart and eyes also strains the kidneys.
Taking ACE inhibitor, ARB, or SGLT2 inhibitor medication consistently if your doctor has prescribed one for kidney protection, even once you feel fine.
Being cautious with over-the-counter painkillers like ibuprofen or other NSAIDs, which can add extra strain to kidneys that are already working harder than normal.
Telling any doctor or radiology staff about your diabetes before a contrast-dye scan, since contrast dye needs extra hydration precautions in people with reduced kidney function.

Painkillers Deserve a Second Thought

Occasional use of paracetamol is generally fine, but regular or high-dose use of NSAIDs (ibuprofen, diclofenac, and similar) can reduce blood flow to kidneys that are already under extra pressure from diabetes. If you need regular pain relief, ask your doctor which option is safest for your kidney health.

“An annual urine and blood test catches kidney strain years before any physical symptoms ever appear — and catching it early is exactly what makes it treatable.”

Keep a log of your annual lab tests

Record your annual UACR and eGFR numbers in Diatic to review trends with your doctor.

Log a reading

Frequently asked questions

Does pain in my lower back mean I have diabetic kidney disease?

No. Diabetic kidney disease does not cause back pain. Lower back pain is usually caused by muscle strain or kidney stones. Early diabetic kidney changes are entirely painless, which is exactly why they are found through scheduled lab tests rather than symptoms.

Does drinking extra water protect my kidneys?

Staying adequately hydrated helps kidneys flush out waste efficiently, but water alone cannot prevent the strain caused by high blood sugar and high blood pressure. Managing glucose and blood pressure, along with any prescribed protective medication, is the primary protection.

If my UACR test comes back normal, does that mean my kidneys are completely fine?

A normal UACR is a genuinely reassuring result, but it is only checked alongside eGFR because the two measure different things — albumin leakage and overall filtering capacity. Your doctor looks at both together, along with the trend over multiple years, rather than a single number in isolation.

Can diabetic kidney disease be stopped once it is found?

In the earliest stage, protein leakage can often be reduced or reversed with blood sugar control, blood pressure control, and protective medication. In later stages, treatment focuses on slowing further decline rather than full reversal — which is why catching it early, through annual screening, makes such a meaningful difference.