Diabetes Complications: 10 Warning Signs, Screening Tests & How to Protect Your Health

 

Diabetes Complications: 10 Warning Signs, Screening Tests & How to Protect Your Health

Diabetes is not only about having high blood sugar.

Over time, diabetes can affect blood vessels and nerves throughout the body, increasing the risk of problems involving the heart, brain, kidneys, eyes, feet and nervous system. Some complications develop slowly and may cause few symptoms at first, which is why regular medical checkups can be just as important as paying attention to how you feel.

The good news is that diabetes complications are not inevitable. Good diabetes management, appropriate screening, healthy lifestyle habits and timely medical care can help prevent or delay many diabetes-related problems. �

NIDDK +1

This guide explains the major complications, warning signs to know, important screening tests and practical steps you can discuss with your healthcare team.

Medical disclaimer: This article is for general educational purposes and is not a substitute for diagnosis or personalized medical advice. If you have diabetes or symptoms of a serious complication, speak with a qualified healthcare professional.

Why Can Diabetes Cause Complications?

Diabetes occurs when blood glucose levels are too high because the body does not make enough insulin, does not use insulin properly, or both.

When elevated blood glucose persists over time, it can contribute to damage involving blood vessels and nerves. This is one reason diabetes can affect several seemingly unrelated parts of the body.

Common diabetes-related health problems include:

Heart disease

Stroke

Kidney disease

Eye disease

Nerve damage

Foot problems

Gum and dental problems

Sexual and bladder problems

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1. Heart Disease and Stroke

One of the most important long-term concerns with diabetes is cardiovascular disease.

Diabetes can affect blood vessels and is often associated with other cardiovascular risk factors such as high blood pressure and abnormal cholesterol levels.

According to NIDDK, adults with diabetes are nearly twice as likely to develop heart disease or have a stroke compared with adults without diabetes. �

NIDDK

What should you watch for?

Possible emergency warning signs include:

Chest pressure or pain

Shortness of breath

Sudden weakness or numbness

Trouble speaking

Sudden confusion

Sudden vision problems

Sudden loss of balance

A sudden severe headache

A suspected heart attack or stroke requires emergency medical attention.

Do not wait for symptoms to disappear.

2. Diabetic Kidney Disease

Your kidneys continuously filter waste and extra fluid from your blood.

Diabetes can damage the small blood vessels and filtering structures inside the kidneys. Kidney disease can develop without obvious symptoms, particularly during its earlier stages.

That makes screening important.

The 2026 American Diabetes Association Standards of Care recommend assessing kidney function using urine albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) at recommended intervals, including at least annually for people with type 2 diabetes and for people with type 1 diabetes after the specified duration. �

Diabetes Journals

Possible warning signs later on may include:

Swelling

Changes in urination

Persistent fatigue

Nausea

Loss of appetite

However, you should not wait for symptoms before getting screened.

3. Diabetic Eye Disease

Diabetes can damage the small blood vessels in the retina.

One important complication is diabetic retinopathy, which can eventually affect vision.

Other eye conditions, including cataracts and glaucoma, can also occur more frequently in people with diabetes. �

CDC

Possible symptoms include:

Blurred vision

Difficulty seeing clearly

Dark spots or floaters

Changes in vision

Vision loss

But here's an important point:

You may have eye damage before you notice vision changes.

That is why recommended eye examinations matter.

The 2026 ADA Standards of Care include assessment for retinopathy and appropriate eye-care referral as part of diabetes care. �

Diabetes Journals

4. Diabetic Neuropathy: When Diabetes Affects Your Nerves

Diabetic neuropathy means nerve damage caused by diabetes.

Peripheral neuropathy commonly affects the:

Feet

Legs

Hands

Arms

Symptoms can include:

Tingling

Burning

Numbness

Shooting pain

Increased sensitivity

Weakness

Reduced ability to feel temperature or pain

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The problem isn't only discomfort.

If you cannot properly feel your feet, you may not notice a blister, cut or small injury.

That can allow a seemingly minor problem to become infected.

The CDC recommends paying attention to foot problems and seeking medical care for wounds that don't heal or symptoms such as burning, tingling, weakness or pain that interfere with daily life. �

CDC

5. Diabetes and Foot Problems

Your feet deserve special attention if you have diabetes.

Nerve damage can reduce sensation, while reduced blood flow can make some wounds harder to heal.

A small blister or cut can therefore become much more serious if it goes unnoticed.

The CDC recommends checking your feet every day, even when they feel normal. �

CDC

A simple daily foot check

Look for:

Cuts

Blisters

Redness

Swelling

Cracks

Sores

Changes in skin color

Signs of infection

Don't ignore a wound simply because it doesn't hurt.

6. Peripheral Artery Disease and Poor Circulation

Diabetes can affect blood vessels throughout the body.

Reduced blood flow to the legs and feet can make wounds more difficult to heal and can increase the risk of serious foot problems. �

NIDDK

Possible symptoms of circulation problems can include:

Leg discomfort when walking

Cold feet

Changes in skin color

Slow-healing wounds

If you notice persistent symptoms, discuss them with your healthcare professional.

7. Low Blood Sugar Can Also Be Dangerous

Not every diabetes emergency comes from high blood sugar.

Hypoglycemia means blood glucose is too low.

It can occur particularly in people using certain diabetes medications.

Symptoms may include:

Shaking

Sweating

Hunger

Dizziness

Confusion

Irritability

Difficulty concentrating

Severe hypoglycemia can become an emergency.

The best way to manage your individual glucose targets is to work with your healthcare team rather than trying to create a target yourself.

The 2026 ADA Standards emphasize that glucose goals should be individualized according to health, treatment risks and other personal factors. �

Diabetes Journals

8. Very High Blood Sugar Can Become an Emergency

Extremely high blood glucose can contribute to serious acute conditions such as:

Diabetic ketoacidosis (DKA)

Hyperglycemic hyperosmolar state (HHS)

These conditions require urgent medical assessment.

Possible concerning symptoms can include:

Extreme thirst

Frequent urination

Weakness

Nausea or vomiting

Abdominal pain

Confusion

Difficulty breathing

If someone with diabetes develops severe symptoms or appears confused, very ill or difficult to wake, seek emergency medical care.

9. Mouth and Dental Problems

Diabetes can also affect oral health.

People with diabetes can develop problems such as:

Gum disease

Dry mouth

Tooth decay

Oral infections

Managing blood glucose, maintaining good oral hygiene and getting regular dental care are important parts of overall diabetes care. �

NIDDK

10. Sexual and Bladder Problems

Diabetes-related nerve and blood-vessel changes can affect sexual and urinary function.

Possible problems include:

Erectile dysfunction

Vaginal dryness

Bladder problems

Changes in sexual sensation

These symptoms can be uncomfortable to discuss, but they are legitimate medical concerns.

If you experience persistent changes, tell your healthcare professional.

There may be treatable causes beyond diabetes itself.

The Diabetes “ABC” Approach

One of the simplest ways to think about diabetes management is the ABC approach.

A = A1C

A1C provides information about average blood glucose over approximately the previous 2–3 months.

For many nonpregnant adults, the 2026 ADA Standards list an A1C goal below 7%, but importantly, goals should be individualized. �

Diabetes Journals

B = Blood Pressure

High blood pressure can increase the risk of cardiovascular, kidney, brain and eye complications.

C = Cholesterol

Managing cholesterol is an important part of reducing cardiovascular risk.

And don't forget smoking

If you smoke, quitting can significantly improve cardiovascular health and reduce other health risks.

NIDDK specifically identifies blood glucose, blood pressure, cholesterol and smoking cessation as important components of reducing diabetes-related complications. �

NIDDK +1

Diabetes Complication Screening Checklist

Instead of waiting until you develop symptoms, ask your healthcare team what screening schedule is appropriate for you.

Area

What may be checked

Blood glucose

A1C and/or other glucose monitoring

Blood pressure

Regular BP measurement

Cholesterol

Lipid testing

Kidneys

UACR + eGFR

Eyes

Recommended diabetic eye examination

Nerves

Neuropathy assessment

Feet

Foot examination

Teeth

Dental examination

Heart

Cardiovascular risk assessment

The exact frequency depends on your diabetes type, duration, age, other health conditions, medications and individual risk.

7 Everyday Habits That Can Help Protect Against Complications

There is no single food, supplement or “detox” that can eliminate diabetes complications.

Instead, focus on consistent habits.

1. Follow your diabetes treatment plan

Take prescribed medication as directed and don't change medication doses without medical guidance.

2. Monitor your blood glucose as recommended

Your healthcare team can tell you how often you should check.

3. Stay physically active

Choose activities that are appropriate for your health and fitness level.

4. Build a balanced eating pattern

Focus on nutrient-dense foods and an eating pattern that fits your diabetes care plan.

5. Maintain a healthy weight when appropriate

For people who are overweight or have obesity, even modest weight loss may improve some metabolic health measures.

6. Don't smoke

Smoking adds cardiovascular and vascular risk.

7. Keep your appointments

Screening can detect some complications before symptoms become obvious.

When Should Someone With Diabetes Seek Urgent Help?

Get urgent medical attention for symptoms such as:

🚨 Possible heart attack

Chest pressure or pain

Shortness of breath

Pain spreading to the arm, shoulder, back, neck or jaw

🚨 Possible stroke

Sudden facial drooping

Sudden weakness or numbness on one side

Sudden difficulty speaking

Sudden confusion

Sudden vision problems

Sudden severe balance problems

🚨 Severe diabetes-related illness

Severe vomiting

Confusion

Difficulty breathing

Loss of consciousness

Severe symptoms associated with very low or very high blood glucose

For suspected heart attack or stroke, call 911 in the United States rather than driving yourself to the hospital. NIDDK lists sudden neurological symptoms and several heart-attack symptoms as reasons for immediate emergency care. �

NIDDK

The Most Important Takeaway

Diabetes complications don't always announce themselves with dramatic symptoms.

Your eyes may need attention before your vision changes.

Your kidneys can be affected before you feel kidney symptoms.

Nerve damage can reduce sensation before a serious foot wound develops.

That's why diabetes care isn't simply about checking a glucose number.

It is about protecting your heart, brain, kidneys, eyes, nerves and feet over the long term.

Regular screening + appropriate treatment + healthy daily habits can help reduce the risk of serious complications.

Frequently Asked Questions

Can diabetes complications be prevented?

Many diabetes-related complications can be prevented or delayed through appropriate glucose management, blood-pressure and cholesterol management, smoking cessation, screening and other individualized care. �

NIDDK

Can you have diabetes complications without symptoms?

Yes. Some complications, particularly kidney and eye disease, may have few noticeable symptoms during earlier stages. That's why recommended screening is important.

What is the most common diabetes nerve problem?

Peripheral neuropathy is the most common type of diabetic neuropathy and commonly affects the feet and legs. �

NIDDK

How often should someone with diabetes have kidney testing?

The 2026 ADA Standards recommend UACR and eGFR assessment at least annually for people with type 2 diabetes and for people with type 1 diabetes after at least five years of disease duration, with more frequent monitoring when CKD is present. Individual care may differ. �

Diabetes Journals

Is every person with diabetes supposed to have the same A1C goal?

No. The 2026 ADA Standards emphasize individualized goals. A goal below 7% is appropriate for many nonpregnant adults, but more or less stringent goals can be appropriate depending on the person's circumstances. �

Diabetes Journals

References & Further Reading

For a U.S. audience, use authoritative sources rather than random health websites:

CDC — Diabetes complications and foot care CDC Diabetes⁠�

NIDDK — Diabetes and preventing complications NIDDK Diabetes⁠�

American Diabetes Association — 2026 Standards of Care ADA Standards of Care 2026⁠�