The earlier chapters were mostly about glucose. This one widens the lens. Glucose is one of several numbers that decide how your blood vessels and organs fare over decades. Blood pressure, cholesterol, kidney tests, eye exams and not smoking matter alongside HbA1c, and some of them are easier to change than you might expect. Chapter 4 introduced the glucose numbers and promised the rest. Here they are.

We start with how high glucose harms vessels and organs, and with the warning signs of a heart attack or stroke that everyone should know. We then go through the numbers and checks that protect you: blood pressure, cholesterol, kidneys, eyes, liver and a handful of others. We finish with a yearly check-up plan you can print, take to appointments and adapt to whatever care is available where you live. Feet are covered in Chapter 15.

14.1 How High Glucose Harms Vessels and Organs

Small vessels and large vessels

Doctors divide diabetes complications into two families. Microvascular complications affect the smallest blood vessels: the retina at the back of the eye (retinopathy), the kidney's filters (kidney disease, or nephropathy) and the small vessels that feed nerves (neuropathy). Macrovascular complications affect the large arteries: heart attack, stroke and poor circulation in the legs. The US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains that high glucose damages blood vessels and the nerves that control the heart, and that adults with diabetes are nearly twice as likely as other adults to have heart disease or stroke, often at a younger age.[@niddkheart]

Glucose is not the only cause. Blood pressure and cholesterol also injure vessel walls, and they often travel together with type 2 diabetes. That is why the protective plan has several parts, sometimes summarised as the ABCs: A for HbA1c, B for blood pressure, C for cholesterol, and S for stopping smoking.[@niddkheart] Improving any one helps; improving all of them helps most.

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Early effort pays off later

The best evidence that early effort matters comes from two long studies. In the UK Prospective Diabetes Study, 4,209 people with newly diagnosed type 2 diabetes were assigned to intensive or conventional treatment. The HbA1c gap between the groups disappeared within a year of the trial ending, yet ten years later the group first treated intensively with a sulfonylurea or insulin still had 24% less microvascular disease, and new reductions in heart attack (15%) and death from any cause (13%). A separate metformin comparison showed a 33% lower rate of heart attack.[@holman2008] In type 1 diabetes, people intensively treated in the Diabetes Control and Complications Trial [@dcct1993] later had 42% fewer cardiovascular events over follow-up (57% fewer for heart attack, stroke or cardiovascular death), even though average HbA1c in the two groups had converged.[@nathan2005] Researchers call this the legacy effect or metabolic memory.

The practical message is encouraging and blame-free. Good years count, and they keep counting. It is also never too late to start protecting yourself; the sections below are about what you can do from today.

Heart attack and stroke: know the signs

Call your local emergency number straight away for any of these. Do not wait to see whether they pass, and do not drive yourself.

• Heart attack: pressure, squeezing or pain in the chest lasting more than a few minutes; discomfort in the arm, shoulder, back, neck, jaw or stomach; shortness of breath; cold sweat, light-headedness, nausea or unusual, extreme tiredness.[@niddkheart][@ahaheart]
• Women more often report shortness of breath, nausea or vomiting, back, shoulder or arm pain and unusual weakness, and may have little or no chest pain.[@ahaheart]
• If you have nerve damage, you may not feel chest pain at all, so a "silent" heart attack is possible.[@niddkheart] Treat sudden breathlessness, sweating or unexplained exhaustion as an emergency.
• Stroke: sudden weakness or numbness of the face, arm or leg, usually on one side; difficulty speaking or understanding; loss of balance or dizziness; sudden vision problems; or a severe headache.[@niddkheart] Even if symptoms fade, get to hospital immediately.

Chapter 13 covers glucose emergencies such as severe lows and ketoacidosis. Heart failure, where the heart pumps less well, usually shows as breathlessness on effort or lying flat, swollen ankles and fast weight gain; report these to your team promptly rather than waiting for the next visit. Modern diabetes medicines can reduce hospital admissions for heart failure, as you will see below.

14.2 The Numbers and Checks That Protect You

Blood pressure

High blood pressure often causes no symptoms, yet it damages the heart, brain, kidneys and eyes. The World Health Organization (WHO) estimates that 1.4 billion adults aged 30 to 79 had hypertension in 2024, and that about 44% of them did not know it.[@whohtn] For people with diabetes, the American Diabetes Association (ADA) advises a target of 130/80 mmHg or lower if it can be reached safely, and encourages a systolic (top) number below 120 for people at high risk of heart or kidney disease. Its clinician handout treats readings above 120/80 as the point at which lifestyle measures should begin.[@ada2026htn] Targets differ between organisations and between people: WHO defines hypertension at 140/90, and older or frailer adults may be given a looser goal. Ask your team what your own target is.

What helps, according to the ADA and WHO:

• Less salt. WHO advises under 5 g of salt (under 2 g of sodium) a day; most of it comes from processed food, sauces and stock cubes rather than the salt shaker.[@whohtn][@ada2026htn]
• Weight loss and a vegetable-, fruit- and legume-rich diet (Chapter 6), and regular activity, at least 150 minutes a week of moderate exercise (Chapter 9).[@ada2026htn][@whohtn]
• Moderate alcohol, which WHO puts at no more than one drink a day for women and two for men; less is better.[@whohtn]
• Medicines. If lifestyle is not enough, the ADA lists ACE inhibitors, angiotensin receptor blockers (ARBs) and calcium channel blockers among the usual choices.[@ada2026htn] Doses and combinations are for your doctor. Never stop these on your own; if you feel dizzy or faint, or you are ill and cannot drink, phone your team.

WHO notes that home devices can be used, although professional assessment remains important;[@whohtn] a validated home monitor can show your usual level better than a single clinic reading. Sit quietly for a few minutes, keep your arm supported at heart height, and note the readings for your appointments. If you have kidney disease or take certain blood-pressure medicines, ask your team before using a potassium-enriched salt substitute.

Cholesterol and statins

Cholesterol travels in the blood on particles; the one that builds up in artery walls is LDL cholesterol. The ADA's 2026 handout advises a statin as the first-choice medicine for people with diabetes, with a target LDL below 70 mg/dL (about 1.8 mmol/L, calculated) for people aged 40 to 75 without known heart disease, and below 55 mg/dL (about 1.4 mmol/L, calculated) for people who already have heart or blood-vessel disease. It is reasonable to treat younger adults (20 to 39) with diabetes, and to continue a statin past 75. Ezetimibe or PCSK9 medicines can be added if the target is not met, and lipids are checked at diagnosis, yearly, and 4 to 12 weeks after a change.[@ada2026lipid]

Why statins? A meta-analysis of 14 randomised trials in 18,686 people with diabetes found a 21% proportional reduction in major vascular events for each 1 mmol/L fall in LDL cholesterol, similar to the benefit in people without diabetes.[@ctt2008]

Some people worry about side effects; muscle aches are the most commonly reported. Please tell your doctor about any new symptoms rather than stopping the tablets yourself; there are usually options such as changing the medicine. Aspirin is a separate question. Whether it helps depends on your history and bleeding risk, so start it only on your doctor's advice. Chapter 11 covers glucose-lowering medicines; this chapter gives no doses.

Smoking and vaping

Smokers are 30% to 40% more likely to develop type 2 diabetes, and people with diabetes who smoke have higher risks of heart, kidney, eye and nerve complications and of poor circulation to the feet. Those who quit find it easier to manage their glucose.[@cdcsmoke] Stopping is the single biggest change many people can make. Ask your team about the support available where you live, and about vaping, which they can advise on.

Kidneys

Healthy kidneys filter waste from the blood and keep protein in. Diabetes and high blood pressure can damage the filters so that a small protein called albumin leaks into the urine, often years before you feel anything. Two simple tests catch this: a urine albumin-to-creatinine ratio (uACR) and a blood test that gives your eGFR (estimated filtering rate). The ADA advises both yearly for everyone with type 2 diabetes, and for people with type 1 from five years after diagnosis.[@ada2026ckd][@deboer2022]

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A uACR of 30 mg/g (about 3 mg/mmol) or more is abnormal. Because albumin levels fluctuate, a high result is repeated: the consensus report of the ADA and Kidney Disease: Improving Global Outcomes (KDIGO) asks for a confirmatory sample within 3 to 6 months, and the rule commonly applied is that two of three samples over that period should be abnormal, so one high result does not by itself mean kidney disease. Kidney disease is diagnosed when abnormalities last for more than 3 months.[@deboer2022][@kdigo2024] Fever, vigorous exercise and urinary infection can raise it briefly, so tell the person collecting the sample.

Science Corner: Why the kidney leaks Each kidney holds about a million tiny filters, called glomeruli, each a knot of capillaries with a fine mesh. Long-term high glucose and high pressure stress this mesh, and albumin, which should stay in the blood, begins to pass through. The uACR is a way of detecting that leak. Categories are A1 (under 30 mg/g), A2 (30 to 299) and A3 (300 or more), and the eGFR is graded alongside them.[@deboer2022] Keeping both numbers steady is the goal.

If the kidney tests are abnormal, the news is better than it used to be. The ADA and KDIGO recommend, for the right people and under a doctor's care, several categories of medicine with proven organ-protective effects beyond lowering glucose:

• ACE inhibitors or ARBs (RAS blockers) are the usual first step when albuminuria is present.[@deboer2022]
• SGLT2 inhibitors are recommended in type 2 diabetes with chronic kidney disease and an eGFR of 20 or above. A meta-analysis of three trials in 34,322 people found 11% fewer major cardiovascular events, 23% less cardiovascular death or heart-failure admission, and 45% less kidney-disease progression; the heart-failure and kidney benefits were seen with or without established heart disease.[@kdigo2022][@deboer2022][@zelniker2019]
• GLP-1 receptor agonists cut major cardiovascular events by 14%, death from any cause by 12% and a composite of kidney outcomes by 21% across eight trials in 60,080 people with type 2 diabetes.[@sattar2021]
• Finerenone, a non-steroidal mineralocorticoid receptor antagonist, is considered when albuminuria (30 mg/g or more) persists despite maximum RAS-blocker treatment, if potassium is normal. In a pooled analysis of 13,026 people with type 2 diabetes and chronic kidney disease it lowered cardiovascular events by 14% and kidney events by 23%, with a higher rate of stopping because of raised potassium (1.7% vs 0.6%), which is why blood tests are needed.[@deboer2022][@agarwal2022]

These are relative reductions measured in trial groups, not promises for any individual, and each medicine has its own risks and checks. Chapter 11 explains the medicine families; your doctor will weigh them for you.

Two practical safety points. First, anti-inflammatory painkillers (NSAIDs) such as ibuprofen and naproxen reduce blood flow through the kidneys and can cause sudden kidney injury; the National Kidney Foundation advises people with kidney disease to avoid them, especially with an eGFR under 60, and also if they take ACE inhibitors, ARBs or diuretics.[@nkfnsaid] Ask your pharmacist for kidney-safer options. Second, when you are vomiting, have diarrhoea or cannot drink, you can become dehydrated, and the ADA and KDIGO expect a sick-day plan that specifies when metformin and SGLT2 inhibitors are paused.[@deboer2022] Never pause or restart any medicine on your own; agree the plan with your team beforehand, and keep insulin going unless told otherwise (Chapter 13).[@ada2026s6][@umpierrez2024]

Eyes

Diabetic retinopathy usually causes no symptoms in its early stages, so waiting for blurred vision means waiting too long.[@nei] The ADA advises a dilated eye exam, or retinal photographs read by a specialist or an approved artificial-intelligence system, at diagnosis of type 2 diabetes; then every 1 to 2 years if there is no retinopathy and glucose targets are met, and every year if retinopathy is present. In type 1 diabetes, the first exam is advised 5 years after diagnosis, and pregnancy needs extra checks before conception and in the first trimester.[@ada2026s12] Some eye organisations advise every year; follow your eye doctor.[@nei]

Seek urgent eye care for sudden vision loss, new floating spots or cobweb-like streaks, or sudden blurring. Treatments work best early: anti-VEGF injections, laser and, for bleeding or scarring, surgery. The ADA calls anti-VEGF first-line for most eyes with macular oedema, and laser (panretinal photocoagulation) effective for high-risk proliferative disease.[@ada2026s12][@nei] Retinopathy is not a reason to avoid aspirin if your doctor has advised it.[@ada2026s12] Tell your eye doctor when your glucose-lowering treatment is intensified, since retinopathy should be reassessed then, and before you take up vigorous or heavy-lifting exercise if you have advanced retinopathy (Chapter 9).[@ada2026s12][@kanaley2022]

Liver, nerves and the rest

Fatty liver. Fat in the liver (now called MASLD, Chapter 1) is common in type 2 diabetes, and one in five people with type 2 diabetes has clinically significant liver scarring (fibrosis) without symptoms.[@adamasld2025] The ADA advises risk assessment in everyone with prediabetes or type 2 diabetes using the FIB-4 score, a calculation from age, two liver enzymes and platelet count that is done on routine blood tests. A score under 1.3 rules out advanced fibrosis; 1.3 to 2.67 usually leads to an ultrasound-based stiffness scan (elastography); above 2.67 leads to a liver specialist.[@adamasld2025][@ada2026s4] Weight loss and the medicines used for weight and diabetes are the main treatments, as covered in Chapters 8 and 11.

Nerves. The ADA advises nerve checks from diagnosis of type 2 diabetes, then at least yearly, including a 10-gram monofilament test, and asking about dizziness on standing, feeling full early, sweating changes and erectile problems.[@ada2026s12] Chapter 15 covers the feet.

Sexual and urinary health. Erection difficulties, reduced desire, vaginal dryness, or bladder problems can be a result of nerve, vessel or hormone changes, or of medicines or low mood. They are common, and they are treatable. Ask your doctor; the ADA lists erectile dysfunction among the symptoms to ask about, and advises checking morning testosterone in men with suggestive symptoms.[@ada2026s12][@ada2026s4]

Teeth, gums and hearing. The ADA advises a dental exam at least once a year, with your dentist and doctor coordinating if your medicines need adjusting around procedures.[@ada2026s4] A large US survey found hearing loss about twice as common in adults with diabetes, and 30% more common in those with prediabetes; mention muffled or lost hearing to your team.[@nih2008hearing]

Vaccines. The ADA advises routine vaccines for adults with diabetes, including yearly influenza, pneumococcal, hepatitis B for adults under 60 (optional above), COVID-19, RSV for adults 60 and over at high risk, shingles from age 50 and tetanus boosters every ten years.[@ada2026s4] Schedules differ by country; ask your clinic which apply.

Sleep apnoea. Loud snoring, witnessed pauses in breathing or daytime sleepiness should prompt a sleep evaluation (Chapter 10).[@ada2026s4]

14.3 Your Yearly Check-Up Plan

The calendar

The table brings the checks together. It follows the ADA Standards of Care where sources were read; your team may adjust it for you.

Frequencies with a citation come from the American Diabetes Association's 2026 Standards of Care and its clinician handouts; the blood-pressure row reflects usual practice, so confirm it with your team.

Preparing and keeping records

A short appointment goes further when you arrive prepared. Keep one folder or notebook, on paper or in your phone, with the date and result of each test, your target for each number, your medicines list, and questions. Bring your glucose logs or sensor report (Chapter 12), a home blood-pressure diary if you keep one, and your last eye, kidney and cholesterol results. Ask for results in writing and write down the units, because kidney and lipid results appear as mg/dL or mmol/L in different countries (Chapter 4). The Part 6 toolkit gives you sheets to fill in.

When resources are limited

Not everyone can get every test each year. The ADA and the European Association for the Study of Diabetes, in their consensus report, note that when resources are limited treatment should be prioritised for people at highest risk, including those with kidney or heart disease, and that cost and access affect what is realistic.[@davies2022] Beyond that, no source read for this chapter sets a universal priority list, so ask your team which checks matter most for you.

Key Takeaways

• Diabetes harms small vessels (eyes, kidneys, nerves) and large vessels (heart, brain, legs), often silently, so regular checks matter more than symptoms.
• Blood pressure, cholesterol, kidney health and not smoking protect you as much as glucose does; the ADA advises a blood pressure target of 130/80 mmHg or lower if safe, and LDL below 70 mg/dL (below 55 with known heart disease).
• Good control early has lasting benefits: in the UKPDS and DCCT/EDIC follow-ups, benefits persisted for years after the HbA1c gap narrowed.
• Kidney disease is found by a yearly uACR and eGFR; an abnormal uACR (30 mg/g or more) is checked again over 3 to 6 months. Several medicine families protect the kidney and heart.
• Eye exams start at diagnosis in type 2 diabetes and repeat every 1 to 2 years or as your eye doctor advises; sudden vision changes are urgent.
• Know the signs of a heart attack and stroke, which can be milder or different in women and in people with nerve damage, and call emergency services at once.
• Check fatty liver with FIB-4, keep vaccines up to date, see the dentist yearly, and ask about sexual, urinary and hearing problems.

Action Points

1. Make your check-up list. Copy the table in 14.3 into a notebook or phone and mark which checks you have had this year.
2. Know your numbers and targets. Ask your doctor for your latest blood pressure, LDL, eGFR and uACR, and your own target for each.
3. Book what is missing. Arrange a dilated eye exam, a urine albumin test and a dental visit if they are overdue.
4. Learn the emergency signs. Write the heart attack and stroke signs on the fridge, tell your family, and call for help at once if they appear.
5. Ask before you change medicines. Discuss with your care team any painkillers, blood-pressure, cholesterol or kidney-protecting medicines, sick-day plans and smoking support; never stop or start them alone.

This book is intended for education and does not replace personal medical advice. If you have diabetes or take glucose-lowering medication, please consult your healthcare team before changing your diet, exercise, or treatment.