Diabetes with Complications

Introduction

If your doctor has told you that you have “diabetes with complications,” it usually means that long-standing diabetes has begun to affect one or more organs most often the eyes, kidneys, nerves, heart and blood vessels, or feet. This is a turning point in care, but it is not the end of good health. Many complications can be slowed, stabilised, or partly reversed when they are picked up early and treated carefully.

This guide is written for people who already live with diabetes and who are now dealing with one or more complications, and for the family members who help them. It explains what is happening inside the body, how each type of complication is treated, and what daily care looks like from this point onward. The aim is not to replace your doctor’s advice but to help you understand the landscape so you can take part in decisions about your care.

Complications are not a sign of personal failure. They are a known medical consequence of years of high blood sugar, often combined with high blood pressure, cholesterol problems, smoking, or genetic risk. What matters now is what you and your care team do next.

What Is Diabetes with Complications?

Diabetes is a long-term condition in which the body cannot keep blood sugar (glucose) in a healthy range. Over many years, high glucose damages the inner lining of blood vessels and irritates nerves. The result is a slow narrowing or leaking of small blood vessels and a thickening or hardening of larger ones. When these changes start to affect how organs work, doctors describe the condition as “diabetes with complications.”

Complications are usually grouped into three categories:

• Microvascular complications — damage to small blood vessels. These mainly affect the eyes (retinopathy), kidneys (nephropathy), and nerves (neuropathy).
• Macrovascular complications — damage to large blood vessels. These raise the risk of heart attack, stroke, and poor circulation in the legs.
• Acute complications — sudden, dangerous changes in blood sugar, such as diabetic ketoacidosis (DKA), hyperosmolar hyperglycaemic state (HHS), and severe hypoglycaemia (very low blood sugar).

Why Complications Develop

Complications usually appear when one or more of the following has been present for years:

• Blood sugar that has been higher than target for long periods
• High blood pressure that was not well controlled
• High cholesterol or other lipid problems
• Smoking, which adds further injury to blood vessels
• Late diagnosis of diabetes, meaning damage was already in progress before treatment began
• Long duration of diabetes, even when control has been reasonable

Some people develop complications despite good control, because of genetic and biological factors that are not fully understood. The presence of complications does not mean care was done wrong; it means care now needs to expand to protect the organs that are affected.

Types of Diabetes Complications

Diabetes can affect many organs. Most people with complications have more than one, even if only one is causing symptoms. The main types are described below.

Diabetic Retinopathy (Eye Disease)

Diabetic retinopathy is damage to the small blood vessels in the retina, the light-sensitive layer at the back of the eye. Early changes often cause no symptoms, which is why eye screening is part of standard diabetes care. As the disease progresses, blood vessels may leak fluid, bleed, or stimulate the growth of abnormal new vessels. Diabetes can also cause swelling of the central part of the retina (macular oedema) and raises the risk of cataracts and glaucoma.

Symptoms that suggest progression include blurred or fluctuating vision, dark spots or floaters, difficulty seeing at night, or a sudden change in vision.

Diabetic Nephropathy (Kidney Disease)

Early kidney damage usually causes no symptoms. Later signs may include swelling of the feet, ankles, or face; foamy urine; tiredness; loss of appetite; or rising blood pressure that is hard to control.

Diabetic Neuropathy (Nerve Damage)

Diabetes can damage nerves anywhere in the body. The most common form is distal symmetric polyneuropathy, which affects the feet and lower legs first and then the hands. Symptoms include tingling, burning, sharp or shooting pain, numbness, or a feeling that socks are bunched up when they are not. Numb feet are especially dangerous because injuries can go unnoticed.

Other forms include autonomic neuropathy, which affects nerves that control blood pressure, digestion, bladder, and sexual function. It can cause dizziness on standing, slow stomach emptying (gastroparesis), constipation or diarrhoea, bladder problems, and erectile dysfunction.

Cardiovascular Disease

People with diabetes are at higher risk of coronary artery disease, heart attack, heart failure, stroke, and peripheral arterial disease (narrowing of the arteries in the legs). High blood sugar, high blood pressure, and abnormal cholesterol speed up the build-up of plaque inside arteries.

Warning symptoms include chest pressure or tightness, shortness of breath, pain in the jaw or arm, reduced exercise tolerance, leg pain when walking that eases with rest, and sudden weakness or speech changes (which can signal a stroke and require emergency care).

Diabetic Foot Problems

Diabetes affects the feet through a combination of nerve damage, reduced circulation, and skin changes. Together these raise the risk of ulcers, deep infections, and in advanced cases amputation. A small cut, a blister from a tight shoe, or a callus can grow into a wound that does not heal. Once an ulcer becomes infected, bone infection (osteomyelitis) can follow.

Skin, Mouth, and Other Effects

High blood sugar increases the risk of skin infections, fungal infections, slow wound healing, and dry, itchy skin. Gum disease and tooth loss are more common. Diabetes can also affect hearing, sleep, and mental health, including a higher risk of depression and anxiety.

Acute Complications

Three sudden complications can occur at any time:

• Diabetic ketoacidosis (DKA) — more common in type 1 diabetes; the body burns fat for fuel and produces acidic ketones. Symptoms include nausea, vomiting, abdominal pain, fast deep breathing, fruity-smelling breath, and confusion. DKA is a medical emergency.
• Hyperosmolar hyperglycaemic state (HHS) — more common in type 2 diabetes; very high blood sugar with severe dehydration, often with confusion or drowsiness. Also a medical emergency.
• Severe hypoglycaemia — blood sugar drops too low, causing shakiness, sweating, confusion, seizures, or loss of consciousness. It is most common in people on insulin or certain pills called sulfonylureas.

Causes and Risk Factors

The basic cause of long-term diabetes complications is years of higher-than-target blood sugar. But several other factors decide who develops complications, how severely, and how fast.

Factors That Increase Risk

• Long duration of diabetes (the risk rises with each year)
• Average blood sugar control over time (often measured as HbA1c)
• High blood pressure
• High LDL (“bad”) cholesterol or high triglycerides
• Smoking and tobacco use
• Obesity, especially around the waist
• Family history of kidney disease, heart disease, or eye disease in diabetes
• Sedentary lifestyle
• Sleep disorders such as untreated sleep apnoea

Factors That Are Protective

• Steady, in-range blood sugar over the years
• Well-controlled blood pressure
• Treatment with statins and other lipid-lowering medicines when indicated
• Not smoking
• Regular physical activity
• Regular eye, kidney, foot, and heart screening, even when you feel well

The American Diabetes Association (ADA) and other major societies emphasise that controlling blood pressure and lipids is often as important as blood sugar control for preventing complications — especially for the heart, brain, and kidneys.

Signs and Symptoms of Progression

Because you are reading this as someone who already has complications, the question is usually not “do I have diabetes?” but “is something getting worse, or is a new complication starting?” Many complications develop quietly, so symptoms can appear late. Tell your care team promptly about any of the following.

Eye Changes

• Blurred, distorted, or fluctuating vision
• Dark spots, floaters, or shadows in your field of view
• Sudden loss of vision in part or all of one eye
• Pain or redness in the eye

Kidney Changes

• Swelling of the feet, ankles, or around the eyes
• Foamy or bubbly urine
• Reduced urine output, or much more urine at night
• Persistent tiredness, nausea, itching, or loss of appetite

Nerve Changes

• Tingling, burning, or shooting pain in the feet or hands
• Numbness or loss of feeling
• Dizziness on standing
• Bloating, early fullness, or unexplained diarrhoea or constipation
• Bladder problems or sexual dysfunction

Heart and Circulation Changes

• Chest pressure, tightness, or pain — especially with exertion
• Shortness of breath that is new or worsening
• Pain or cramping in the calves when walking
• Cold, pale, or bluish feet
• Sudden weakness, numbness on one side, slurred speech, or facial drooping — call emergency services immediately

Foot Changes

• Any cut, blister, or wound that is not healing
• Redness, warmth, swelling, or pus around a wound
• Changes in foot shape or new pressure points
• Bad smell from a wound — this can signal serious infection

Many complications develop silently, which is why regular screening tests are part of standard diabetes care even when you feel well.

Diagnosis and Ongoing Evaluation

Once complications are known to be present, the goal of testing changes. Instead of looking for the first signs, your team is tracking how each complication is behaving, whether new ones are appearing, and whether treatment is working.

Tests for Overall Diabetes Control

• HbA1c — gives an average of blood sugar over the past two to three months
• Home glucose monitoring — finger-prick or continuous glucose monitor (CGM) readings
• Lipid profile — cholesterol and triglycerides
• Blood pressure — measured in clinic and often at home
• Weight, waist measurement, and overall body composition

Tests for Specific Complications

• Eyes — dilated eye examination by an ophthalmologist, often with retinal photography or optical coherence tomography (OCT) scans. The American Academy of Ophthalmology recommends regular review, with frequency set by the stage of retinopathy.
• Kidneys — a urine test for albumin (a protein), and a blood test (creatinine) used to calculate eGFR, which estimates how well the kidneys are filtering. KDIGO guidelines recommend at least yearly testing.
• Nerves — foot examination including sensation testing with a monofilament, tuning fork, and reflexes; nerve conduction studies in selected cases.
• Heart — ECG, echocardiogram, exercise tests, or coronary imaging, depending on symptoms and risk.
• Circulation in legs — pulse examination, ankle-brachial index (ABI), and Doppler studies when needed.
• Feet — a structured foot examination at least once a year, and more often if you have neuropathy, deformity, or previous ulcers.

Treatment and Management

Care for diabetes with complications has three main aims: control the underlying diabetes more tightly where it is safe to do so, treat each complication directly, and reduce overall cardiovascular risk. Most patients are looked after by a team that includes an endocrinologist or diabetologist together with specialists in the affected organs.

Optimising Diabetes Control

Targets for blood sugar are individualised. Many adults aim for an HbA1c around 7%, but the target may be higher for older people, those with frequent hypoglycaemia, or those with limited life expectancy, and lower for some younger patients. The ADA stresses that targets should fit the person, not the other way round.

Medicines used to control blood sugar include:

• Metformin — usually the first medicine for type 2 diabetes if the kidneys allow it
• SGLT2 inhibitors — have been shown in trials to protect the kidneys and heart; current guidelines recommend them for many patients with kidney disease, heart failure, or established heart disease
• GLP-1 receptor agonists — injectable medicines that lower glucose, support weight loss, and reduce cardiovascular events in high-risk patients
• DPP-4 inhibitors — oral medicines that modestly lower glucose with low risk of hypoglycaemia
• Sulfonylureas and meglitinides — lower glucose but can cause hypoglycaemia
• Pioglitazone — improves insulin sensitivity
• Insulin — needed in type 1 diabetes and often in advanced type 2 diabetes, especially when other medicines are not enough

The choice of medicine depends on the type of diabetes, which complications are present, kidney function, weight, risk of hypoglycaemia, and personal preferences. Some medicines are favoured because they protect the heart and kidneys beyond their glucose-lowering effect.

Controlling Blood Pressure

High blood pressure speeds up almost every diabetes complication. Targets are individualised but commonly fall around 130/80 mmHg for many adults with diabetes. ACE inhibitors and angiotensin receptor blockers (ARBs) are commonly used first when there is kidney disease or protein in the urine because they protect kidney function. Diuretics and calcium channel blockers are often added.

Controlling Cholesterol and Cardiovascular Risk

Statins are the foundation of cardiovascular risk reduction in diabetes. Doctors commonly prescribe them for adults with diabetes who have established heart disease, kidney disease, or other risk factors. Additional medicines such as ezetimibe or PCSK9 inhibitors may be added in selected patients. Low-dose aspirin is considered for some people with established cardiovascular disease but is not used routinely for everyone with diabetes because of bleeding risk.

Treating Specific Complications

Eye disease. Treatment depends on the stage. Mild retinopathy is monitored more closely. Macular oedema and more advanced retinopathy may be treated with injections of anti-VEGF medicines into the eye, laser treatment (panretinal photocoagulation or focal laser), or vitrectomy surgery for advanced bleeding or scarring. Cataracts can be treated with surgery, and glaucoma with eye drops, laser, or surgery.

Kidney disease. Treatment focuses on slowing progression with blood pressure control, ACE inhibitors or ARBs, SGLT2 inhibitors when appropriate, and increasingly a newer class of medicines called non-steroidal mineralocorticoid receptor antagonists. Diet adjustments (such as moderating salt and, in later stages, protein) may be advised by a renal dietitian. In advanced disease, dialysis or kidney transplant become part of the conversation.

Nerve damage. The underlying nerve damage is hard to reverse, but symptoms can often be eased. Medicines used for neuropathic pain include certain antidepressants (such as duloxetine or amitriptyline) and anticonvulsants (such as pregabalin or gabapentin). Topical creams and patches may help in some cases. Autonomic symptoms — such as dizziness, gastroparesis, or bladder issues — are treated individually.

Heart and circulation. Treatment may include medicines for blood pressure, cholesterol, and angina; procedures such as coronary angiography, stenting, or bypass surgery; treatment for heart failure; and procedures to open or bypass blocked leg arteries.

Foot problems. Ulcers are treated with wound care, offloading (special shoes, casts, or boots to take pressure off the wound), infection control, and sometimes surgery. The International Working Group on the Diabetic Foot (IWGDF) emphasises specialist multidisciplinary foot care to reduce amputation risk.

Multidisciplinary Care

Because complications affect several organs at once, care often involves:

• Endocrinologist or diabetologist
• Ophthalmologist (eyes)
• Nephrologist (kidneys)
• Cardiologist (heart)
• Neurologist (nerves)
• Vascular surgeon (circulation)
• Podiatrist or foot care specialist
• Dietitian, diabetes educator, and mental health professional

Good outcomes depend on these specialists communicating with one another rather than working in isolation.

Lifestyle and Self-Management

Daily habits remain powerful at every stage of diabetes, including when complications have already begun. They support — rather than replace — medicines.

Eating Well

There is no single diabetes diet. Most current guidance favours a pattern that is rich in vegetables, whole grains, legumes, nuts, healthy oils, and lean protein, with limited added sugars, refined carbohydrates, processed meats, and sugary drinks. Mediterranean-style and DASH-style eating patterns are widely supported by the evidence.

Once complications are present, diet may need further tailoring:

• Kidney disease — salt is usually moderated; protein intake may be adjusted; potassium and phosphorus may need to be limited in advanced stages
• Heart disease — saturated fat and salt are usually reduced
• Gastroparesis — smaller, more frequent meals, lower in fat and fibre
• Weight management — modest weight loss often improves blood sugar, blood pressure, and cholesterol

A dietitian who knows about diabetes and the specific complications can build a plan that is realistic for your culture, schedule, and budget.

Physical Activity

Regular activity helps lower blood sugar, improve insulin sensitivity, support heart health, lift mood, and protect strength and balance. Many adults aim for around 150 minutes a week of moderate activity such as brisk walking, with two or more sessions of strength training. People with complications often need adjustments:

• Severe retinopathy may make heavy lifting, high-impact, or breath-holding exercise unsafe until the eye disease is treated
• Peripheral neuropathy raises the risk of foot injury, so well-fitting footwear and lower-impact activities (cycling, swimming) may be preferred
• Heart disease may require an exercise test and an individualised plan
• Hypoglycaemia risk may need adjustments to medicines or carbohydrate intake around exercise

If you are unsure, ask your team to help build a safe plan before starting.

Foot Care

Daily foot care matters enormously when nerve damage or circulation problems are present:

• Look at your feet every day, including between the toes — use a mirror if needed
• Wash and dry feet carefully, especially between the toes
• Moisturise dry skin but not between the toes
• Cut toenails straight across; have a professional do it if your sight or reach is limited
• Never walk barefoot, even indoors
• Check shoes for stones, rough seams, or worn linings before putting them on
• Choose well-fitting shoes with adequate room for the toes
• See a foot specialist promptly for any new wound, blister, or change in colour

Smoking, Alcohol, and Sleep

Stopping smoking is one of the single most useful changes for anyone with diabetes complications. It slows kidney disease, reduces heart and stroke risk, and improves circulation in the feet. Support is available through counselling and medicines — ask your team.

If you drink alcohol, limit it, and be aware that alcohol can cause low blood sugar, especially with insulin or sulfonylureas. Untreated sleep apnoea worsens blood pressure and blood sugar; if you snore heavily or feel sleepy during the day, ask about a sleep assessment.

Mental Health

Living with diabetes complications can bring frustration, fear, grief, and what is sometimes called “diabetes distress.” Depression and anxiety are more common in people with diabetes than in the general population, and they make self-care harder. Counselling, peer support, and treatment when needed are part of comprehensive care, not optional extras.

Monitoring, Targets, and Follow-Up

Once complications are present, monitoring becomes more structured. Targets are agreed between you and your team based on your overall health, risk of hypoglycaemia, and life situation.

What Follow-Up Usually Includes

• Regular reviews with your endocrinologist or diabetologist (often every three to six months)
• HbA1c usually every three to six months
• Yearly kidney tests (urine albumin and blood creatinine), more often if disease is advancing
• Yearly dilated eye examination, more often depending on retinopathy stage
• Yearly comprehensive foot examination, more often with high-risk feet
• Blood pressure and lipid checks
• Cardiovascular review if symptoms or risk factors warrant
• Vaccinations such as influenza, pneumococcal, COVID-19, and others as advised
• Dental check-ups, since gum disease and diabetes affect each other

Why Adherence Matters

Skipping medicines, missing appointments, or changing doses without guidance is one of the strongest drivers of complication progression. If a medicine is causing side effects, is hard to afford, or is hard to remember, tell your team rather than stopping on your own — alternatives almost always exist.

Living with Diabetes Complications

A diagnosis of complications can feel like a sudden change in identity. Many people describe a phase of fear, anger, or guilt before they settle into a new rhythm. With time, structured care, and support, most people regain a sense of control.

Work, Travel, and Daily Life

Most people with diabetes complications continue to work and travel. Practical steps that help include:

• Carrying medicines and glucose-lowering supplies in hand luggage when flying
• Asking about time-zone adjustments for insulin and medicine timing
• Keeping a written summary of your conditions, medicines, allergies, and your doctor’s contact
• Wearing or carrying medical identification
• Planning meals and breaks rather than skipping them
• Building in extra rest, especially during periods of heat or illness

Family and Caregivers

Family members often take on practical tasks — reminders, appointments, foot inspection, meal planning — and emotional support. Learning to recognise and treat hypoglycaemia is important for anyone living with you. So is knowing the signs of a heart attack, stroke, or diabetic emergency, and when to call for help.

Sexual Health

Diabetes can affect sexual function in both men and women, through nerve damage, circulation changes, hormonal factors, and the emotional weight of chronic illness. These topics are often left unspoken but they are part of standard care. Effective treatments exist for many causes and your doctor will not be surprised by the question.

Complications if Care Is Delayed

Without treatment, the major complications of diabetes can progress to:

• Severe vision loss or blindness
• Kidney failure requiring dialysis or transplant
• Chronic, disabling neuropathic pain
• Heart attack, heart failure, or stroke
• Non-healing foot ulcers and amputation
• Recurrent infections and hospitalisations

This is not a prediction for your future. It is a description of what these conditions can do when left untreated. Early and consistent care has been shown in many large studies to reduce all of these outcomes substantially.

Diabetes Complications in Children and Young Adults

Most children with diabetes have type 1 diabetes, although type 2 diabetes is increasingly seen in adolescents with obesity. Complications usually take many years to develop, but they can begin during childhood or young adulthood, especially if blood sugar has been hard to control or if there are additional risk factors.

Screening recommendations from paediatric and adolescent diabetes societies generally include:

• Annual eye examination starting a few years after diagnosis of type 1 diabetes, and at or shortly after diagnosis of type 2 diabetes
• Annual kidney screening (urine albumin) after the same intervals
• Annual foot examination once neuropathy risk applies
• Blood pressure and lipid checks at regular intervals
• Mental health screening — depression, anxiety, eating disorders, and diabetes distress are more common in young people with diabetes

Care for a young person with diabetes complications involves the family, the school or college, and a paediatric or adolescent diabetes team. Transition planning — moving from paediatric to adult care — is an important step around the late teens and early twenties, and it is usually a structured process rather than a sudden handover.

Preventing Progression and New Complications

Once complications are present, prevention becomes about slowing what has started and stopping new problems from developing. The most useful actions are also the most studied:

• Aim for the blood sugar target your doctor has agreed with you
• Keep blood pressure in target range
• Take statins or other lipid-lowering medicines as prescribed
• Take medicines that protect the kidneys and heart (such as ACE inhibitors, ARBs, SGLT2 inhibitors, and GLP-1 receptor agonists) as prescribed
• Do not smoke; get support if you do
• Attend screening appointments — eyes, kidneys, feet, heart — even when you feel well
• Move daily, within a plan that fits your complications
• Eat in a pattern that supports your weight, blood sugar, and organ health
• Look after your mental health
• Keep vaccinations up to date

No single step is a guarantee, but stacked together, these actions have repeatedly been shown in large clinical trials to reduce the risk of heart attack, stroke, kidney failure, blindness, and amputation.

When to Seek Urgent Care

Some symptoms need same-day or emergency attention. Seek urgent help if you have:

• Chest pain or pressure, especially with shortness of breath, sweating, or pain spreading to the jaw or arm
• Sudden weakness, numbness, slurred speech, facial drooping, or trouble seeing — possible stroke
• Severe shortness of breath
• Persistent vomiting, deep fast breathing, fruity-smelling breath, or severe abdominal pain — possible DKA
• Confusion, drowsiness, or fainting
• Severe hypoglycaemia that does not respond to food or glucose
• A foot wound with spreading redness, pus, foul smell, or fever — possible serious infection
• Sudden vision loss in one or both eyes
• Markedly reduced urine output with swelling and breathlessness

If in doubt, contact your care team or go to the nearest emergency department.

Frequently Asked Questions

Can diabetes complications be reversed?

It depends on the complication and how advanced it is. Some changes — such as early kidney damage, mild retinopathy, and early heart disease — can be partly reversed or stabilised with intensive treatment. Others, such as advanced nerve damage or established kidney failure, usually cannot be reversed, but their progression can be slowed and the symptoms can be managed.

Will I need to start insulin now that I have complications?

Not always. Many people with type 2 diabetes and complications continue with oral medicines and non-insulin injectables, especially newer medicines that protect the kidneys and heart. Insulin is added when blood sugar cannot be brought into range with other treatments, or when specific situations call for it (such as severe infections or hospital stays).

Is it too late for lifestyle changes to make a difference?

No. Studies consistently show that diet, physical activity, stopping smoking, and weight management continue to improve outcomes at every stage of diabetes, including after complications have developed. Lifestyle changes work alongside medicines, not instead of them.

How often should I see my doctor?

Most people with complications see their main diabetes doctor every three to six months, with additional visits to specialists for eyes, kidneys, heart, or feet as needed. Your team will set the schedule based on your specific situation.

Are some types of diabetes more likely to cause complications?

Both type 1 and type 2 diabetes can cause the full range of complications. What matters most is duration of disease, blood sugar control, blood pressure, lipids, smoking, and genetics, rather than the type itself.

Do I need to follow a special diet?

You will likely benefit from a structured eating plan, especially if you have kidney disease, heart disease, or gastroparesis. A dietitian who works with diabetes can adjust the plan to your culture, preferences, and other conditions.

Can I still exercise if I have neuropathy or retinopathy?

In most cases yes, but the type of exercise may need to be adjusted. Lower-impact activities, well-fitting footwear, and an exercise plan reviewed by your doctor can help you stay active safely. Advanced retinopathy may temporarily limit heavy lifting and high-impact activity until eye treatment is completed.

Will my children inherit diabetes complications?

What can be inherited is a tendency toward diabetes and toward certain risk factors (high blood pressure, kidney susceptibility, heart disease). Complications themselves develop because of how diabetes is managed and how long it has been present. Encouraging healthy habits in the family is helpful regardless.

I feel low and anxious about my diagnosis. Is that normal?

Yes, and you are not alone. Depression, anxiety, and diabetes distress are common, and they make self-care harder. Talking to your doctor about how you are feeling is part of good diabetes care. Counselling, peer support groups, and treatment when needed all help.

Conclusion

Diabetes with complications is a serious diagnosis, but it is also a managed one. Modern care — with newer medicines that protect the heart and kidneys, advances in eye and foot care, better tools for monitoring blood sugar, and team-based follow-up — has changed the outlook for people in your situation. Many complications can be slowed, some can be partly reversed, and the worst outcomes can often be prevented.

The most useful steps are not dramatic. They are steady: take your medicines, attend your screening appointments, keep moving within a plan that suits your body, eat in a pattern that supports your organs, do not smoke, and ask for help when you need it. The work is shared between you, your family, and your care team, and it pays back over years.

Knowing what is happening inside your body and what each treatment is for makes it easier to take part in those decisions and that, more than any single medicine, is what protects long-term health.