The good news is that much of this damage is preventable. It depends on a few small habits (looking, washing, protecting) and on knowing which signs mean "call today". It also depends on advice that fits real life: in many countries people go barefoot at home, remove shoes at the door of a temple or mosque, wear sandals all year round, and sit or squat on the floor.

Section 15.1 explains why feet are at risk and how professionals check them. Section 15.2 covers daily care, footwear, culture, and what to do when something goes wrong. Section 15.3 widens the view to skin elsewhere on the body, including changes at injection and sensor sites.

15.1 Why Feet Are at Risk

Three problems that add up

Three conditions make feet vulnerable, and they often occur together.

Nerve damage (neuropathy). Over years, high glucose can damage the nerves that carry sensation from the feet. The key concept is loss of protective sensation: you can no longer feel pain, pressure, or temperature well enough to be warned. Neuropathy can also change the shape of the foot and dry out the skin. The ADA notes that many cases of neuropathy have no symptoms at all, which is why the feet need to be examined and not simply asked about.[@ada2026s12]

Poor blood flow (peripheral artery disease). Narrowed arteries in the legs deliver less oxygen and fewer infection-fighting cells to the feet. Wounds heal more slowly, and infections can spread faster.[@schaper2024]

Foot deformity. Claw toes, bunions, and a high or flattened arch concentrate pressure on small areas of skin.

Together they set up the sequence that leads to an ulcer. A review in the New England Journal of Medicine describes foot ulcers as commonly caused by repeated stress over an area of the foot exposed to high pressure or shearing force in a person with neuropathy. The same review points out that people who lack the warning of pain may not take preventive measures, such as wearing their prescribed footwear at all times.[@armstrong2017] A tight strap, a pebble, a new pair of shoes, a fissure in dry heel skin: any of these can begin the chain.

Science Corner: Watching skin temperature Because a numb foot does not report damage, injury is often found late. Inflamed skin over a developing sore is warmer than the same spot on the other foot, and the IWGDF prevention guideline suggests that people at moderate or high risk could be coached to measure the skin temperature of both feet daily; if the two feet differ by more than 2.2 degrees Celsius on consecutive days, they should reduce activity and seek professional evaluation.[@bus2024]

How common, and how serious

A systematic review and meta-analysis of studies from around the world estimated the global prevalence of diabetic foot ulcer, meaning the proportion of people with diabetes who have one at a given time, at 6.3 percent (95 percent confidence interval 5.4 to 7.3). Regional estimates ranged from 3.0 percent in Oceania to 13.0 percent in North America (Asia 5.5, Africa 7.2), partly reflecting how and in whom each study measured.[@zhang2017]

Over a lifetime the risk is greater. The NEJM review estimates that between 19 and 34 percent of people with diabetes are likely to be affected. Ulcers also tend to come back: roughly 40 percent within one year, almost 60 percent within three years, and 65 percent within five. The risk of death at five years for a person with a foot ulcer is 2.5 times that of a person with diabetes who has no ulcer, and about 20 percent of moderate or severe foot infections lead to some level of amputation.[@armstrong2017]

Read these figures as a reason for attention, not for fear. The same review adds that most recurrent foot ulcers are preventable when the recommended measures are put in place.[@armstrong2017] The International Working Group on the Diabetic Foot (IWGDF) notes that foot disease and amputation are rising fast, especially in middle- and lower-income countries, and that where prevention principles have been put into practice, diabetes-related amputations have become less frequent.[@schaper2024]

What a foot check involves

The ADA recommends a comprehensive foot evaluation at least annually, with shoes and socks off: inspection, a look for deformities, a test of sensation, and an assessment of blood supply. People who already have sensory loss, a past ulcer, or an amputation should have their feet inspected at every visit.[@ada2026s12]

According to the IWGDF, the yearly screening includes three questions: is the skin intact, has protective sensation been lost, and are there signs of poor circulation?[@schaper2024]

• Sensation is tested with a 10-gram monofilament, a thin nylon fibre pressed against the sole until it bends; a 128 Hz tuning fork for vibration; or, where those are not available, a light touch on the tips of the toes.
• Circulation is judged by asking about leg pain on walking (claudication) and by feeling the pulses in the feet. Ankle and toe blood pressures are measured when a problem is suspected.[@schaper2024]

{{fig:F15-B}}

Your risk category

The IWGDF sorts people into four categories, and the category sets how often the feet should be checked.

IWGDF 2023 risk stratification (PAD = peripheral artery disease). Adapted from the IWGDF practical guideline.[@schaper2024]

Ask your team which category you are in. In footwear studies from low- and middle-income countries, many people had never had their feet inspected or been told how to look after them;[@reddie2023] if that is you, ask for an exam first.

15.2 Daily Foot Care That Works

The two-minute daily check

{{fig:F15-A}}

The IWGDF advises people at risk to wash and examine their feet every day, learn to recognise early warning changes, and contact a trained health professional quickly if they find one.[@schaper2024] The ADA suggests using touch or an unbreakable mirror for the soles.[@ada2026s12] If eyesight or flexibility makes this hard, ask a family member to be your second pair of eyes.

Daily foot check. The layout is this book's; the checks follow the IWGDF and ADA advice in this section.[@schaper2024][@ada2026s12]

Washing, moisturising, nails

The IWGDF advises: wash and dry between the toes carefully, use an emollient (a moisturiser) on dry skin, and cut toenails straight across.[@schaper2024][@bus2024] Two additions from the author, not from the guidelines: keep moisturiser off the skin between the toes, where trapped moisture encourages fungal infection, and test bath water with your elbow or a thermometer, not your foot.

Calluses, corns, and thick nails deserve professional care. The IWGDF prevention guideline asks that pre-ulcerative lesions, excess callus, ingrown toenails, and fungal infections be treated by a trained professional.[@bus2024] Chemical corn removers, razor blades, and "bathroom surgery" are best avoided, because they can damage skin you cannot feel.

Heat: a hidden danger

If you cannot feel heat properly, water that seems pleasantly warm can scald. A case series described three people with diabetic neuropathy who suffered severe foot burns from thermal footbaths, with full-thickness burns covering 4 to 5 percent in the cases reported. The burns became infected, and in one case a toe was amputated. The authors advised checking water temperature with a thermometer, limiting soaking time, and going to hospital early if a wound appears.[@loh2014] The same caution, added by the author and not drawn from that report, applies to hot-water bottles, heating pads, heaters under a desk, car seat warmers, and hot sand, paving, or tiles in the sun.

Shoes: what fit means

The IWGDF gives concrete rules. The inside length of the shoe should be 1 to 2 centimetres longer than the foot; the inside width should match the width of the foot at the joints at the base of the toes; and the height should leave room for all the toes. If ordinary shoes cannot fit, a specialist can prescribe therapeutic footwear such as extra-depth shoes, custom-made shoes, or custom insoles. The guideline adds that a shoe that has caused an ulcer should never be worn again.[@schaper2024] The ADA recommends therapeutic footwear for people with loss of protective sensation, deformity, calluses, poor circulation, or a history of ulcer or amputation.[@ada2026s12]

Check the inside of every shoe with your hand before putting it on, and break new shoes in slowly, inspecting your feet after each session (author's suggestions).

Barefoot, sandals, and real life

The IWGDF says: "always walk with socks and shoes, whether indoors or outdoors", and that socks alone do not protect the feet.[@schaper2024] That is sound for a foot with no feeling, but it assumes conditions many readers do not live in.

A review of 25 studies from 13 low- and middle-income countries found that sandals and flip-flops were the most common footwear among people with diabetes (23 to 98 percent across studies, median 76 percent), closed shoes far less common (3 to 70 percent, median 16 percent), and therapeutic footwear rare (0 to 5.3 percent). The reasons were practical: cost, hot and wet climates, and frequent removal of shoes for cultural reasons. The authors asked health systems to consider whether international guidelines suit local conditions.[@reddie2023]

So what can you do? These are the author's suggestions, not guideline statements, and you should check them with a foot professional:

• Know your risk. With normal sensation (category 0), occasional barefoot time on clean, smooth floors is a far smaller risk than with numb feet. If you have lost sensation, indoor footwear matters as much as outdoor.
• Choose the safest sandal, not the cheapest. A sandal with a thick sole, a heel strap, and a soft, wide upper is a better choice than a thin flip-flop, whose strap between the toes can rub. Inspect the strap sites daily. Firm-soled house shoes that slip on and off easily suit homes where outdoor shoes stay outside.
• At places where shoes must come off (a temple, a mosque, a relative's house), look at the floor before walking, keep to clean, smooth ground, wear clean socks where the custom allows, and do the daily check that evening.
• Beaches and hot ground. Wear water shoes at the shore, where shells, rocks, and hot sand can injure a foot silently.
• Ritual washing. Ablution before Muslim prayer includes washing the feet up to the ankles and between the toes,[@khan2025] which is good hygiene provided the skin between the toes is dried well afterwards. A review cites one South African study of athlete's foot in 85 percent of Muslim men versus 41 percent of controls, attributed to communal washing areas and barefoot prayer surfaces.[@khan2025]
• Squatting and kneeling. After prayer, gardening, or floor-level work, look for pressure marks on the tops of the toes and ankles, and use a cushion or mat.

Smoking, walking, and staying active

Smoking harms blood vessels, and the ADA advises smoking-cessation counselling for smokers with prior complications.[@ada2026s12] Activity is still valuable: Chapter 9 describes options such as cycling, swimming, and chair exercises when neuropathy is present.[@colberg2016] Protect the foot while you are active with well-fitting shoes and socks, inspect afterwards, and rest a spot that looks irritated.

When to seek care the same day

Any break in the skin of a foot with diabetes is a medical matter; do not wait to see whether it gets better. Call your team or go to a clinic the same day for:

• a blister, cut, scrape, or crack that does not look like it is healing;
• new redness, warmth, swelling, or pain, or new numbness or tingling;
• skin that turns black, blue-grey, or very pale, or a new foul smell;
• a hot, red, swollen foot, even with no wound.

Go to an emergency service if a foot problem comes with fever, chills, confusion, vomiting, or you feel very unwell, or if redness is spreading up the leg. These may be signs that infection has spread through the body. The IWGDF defines infection as at least two signs of inflammation (redness, warmth, induration, and pain or tenderness) or pus, and says infection in a foot with poor blood flow can spread rapidly and may need urgent surgical assessment.[@schaper2024]

Science Corner: The hot, red, swollen foot A foot with neuropathy that is red, hot, and swollen might be infected, but it might have Charcot neuro-osteoarthropathy: a sterile inflammatory process in which bones and joints are damaged and can collapse. The IWGDF says the diagnosis should be considered in anyone with diabetes and a red, hot, swollen foot. The preferred treatment is a non-removable, knee-high cast, continued until the inflammation settles, which can take many months. Below-the-ankle devices are not recommended.[@schaper2024]

What not to do

Do not cut out corns or lift blisters with scissors, needles, or blades. Do not put home remedies, herbal pastes, oils, strong antiseptics, or heat on a wound. The author's rule of thumb: cover a fresh wound with a clean, dry dressing, keep weight off it, and get it seen. Do not keep walking on an open sore because "it doesn't hurt".

How professionals treat a foot wound

The IWGDF sets out these principles:[@schaper2024]

• Offloading. Taking pressure off the ulcer is the cornerstone of treatment. For a nerve-damage ulcer on the sole, the preferred device is a knee-high cast or walker made non-removable, so that it cannot be taken off at home.
• Cleaning. A professional removes dead tissue and surrounding callus (debridement).
• Infection. Mild infections may be treated with oral antibiotics chosen to target the usual skin bacteria. Deep or severe infection needs urgent assessment for surgery, drainage, and intravenous antibiotics. The choice and dose are for your treating team.
• Blood supply. If an ulcer has not shown signs of healing within four to six weeks despite good management, the team should consider imaging of the arteries and revascularisation, meaning restoring blood flow. Before a major amputation, revascularisation should be considered.
• A team. Care is best delivered by several disciplines, from a general doctor, podiatrist, and diabetes nurse to surgeons, vascular and infection specialists.

Ask what you need to do at home, and what would make the team want to see you earlier.

15.3 Skin, Nails, and the Rest of the Body Surface

Skin conditions are common in diabetes. A 2017 review states that skin disorders occur in about one third of people with diabetes, and bacterial and fungal infections are more common than in people without it.[@lima2017] Most are harmless; a few are early clues that the body's insulin signal is off.

Dry skin and itching

Dry skin (xerosis) is common, and nerve damage can reduce sweating, which makes it worse. A 2025 review names dryness as a frequent cause of chronic itching and supports treating it first with moisturisers.[@dorf2025] Use mild soap, short lukewarm showers, and a moisturiser after washing.

Fungal and bacterial infections

Athlete's foot (tinea pedis) is the most common skin-fungus infection in the review, and thickened, discoloured nails may be fungal. The same review notes candida infections in skin folds, between the fingers and toes, in the nails, and in the mouth, and reports that nearly one in two people with type 2 diabetes have fungal nail infection.[@dorf2025] Fungal infections can open a path for bacteria, and the IWGDF advises treating them to prevent ulcers.[@bus2024] Ask a pharmacist or doctor to confirm the diagnosis before treating.

Skin signs that are not infections

• Acanthosis nigricans. Darker, thickened, velvety skin at the neck, armpits, or groin. It is linked to high insulin levels and is a reliable skin marker of insulin resistance; managing it means addressing insulin resistance itself, through food, activity, weight, and medicine where appropriate.[@dorf2025] Chapter 2 describes what it can mean before diagnosis: in one study, when present, insulin resistance was very likely.[@alvarez2020]
• Diabetic dermopathy. Oval, dull red spots that become brownish, slightly sunken patches, typically on the shins. They cause no symptoms, and a 2025 review reports them in over half of people with poorly controlled type 2 diabetes. It also describes one study where skin severity scores fell as HbA1c fell over 24 months.[@dorf2025]
• Necrobiosis lipoidica. Yellowish-brown, shiny patches, often on the shins, which can ulcerate. They are uncommon, seen in about 0.3 to 1.2 percent of people with type 1 diabetes.[@dorf2025] Ask a dermatologist.
• Skin tags. Small soft growths in the neck or armpit. They occur in about 23 percent of people with diabetes, and the review noted that having 30 or more was associated with a higher chance of type 2 diabetes.[@dorf2025] They are harmless, but many tags are a reason to ask about testing.

Skin at injection, pump, and sensor sites

Insulin injections can cause lipohypertrophy, soft raised lumps where repeated injections happen at the same spot. Chapter 11 explains rotation of sites and needle length;[@ada2026s9] a 2025 review reports lipohypertrophy in about 27 percent of people with diabetes.[@dorf2025] Ask your nurse to feel your sites at review visits, and avoid injecting into lumps. Adhesive patches from glucose sensors and pumps can cause irritation or allergic reactions; the ADA asks that skin reactions be assessed so that device use can continue. Chapter 12 has details.[@ada2026s7] Call your team if a rash spreads, blisters, or oozes.

Sun, cuts, and healing

Numb or dry skin burns easily, so use shade, a hat, and sunscreen on feet and legs in sandal weather (author's suggestion). Higher glucose is widely understood to slow wound healing and weaken defences against infection, so glucose control is part of skin care too. For gums and teeth, see Chapter 14 and ask your dentist for regular checks.

Key Takeaways

• Diabetes can damage the nerves and blood vessels of the feet, so an injury may be painless, slow to heal, and easily infected. Much of the damage is preventable.
• In an NEJM review, 19 to 34 percent of people with diabetes were estimated to develop a foot ulcer in their lifetime; the review also states that most recurrent ulcers are preventable.
• Have your feet examined without shoes at least once a year, and more often if you have numbness, poor circulation, deformity, or a past ulcer. Ask which IWGDF risk category you are in.
• The daily two-minute check, careful washing and drying between the toes, well-fitting shoes, and never going without protection when you cannot feel your feet are the core habits.
• Culture and climate matter: sandals, barefoot homes, and shoe-free places of worship are common. Choose the safest option available, protect the moments you cannot avoid, and check your feet afterwards.
• Any wound, blister, or new red, hot, swollen area needs same-day professional care. Never self-treat with cutting, chemicals, or heat.
• Dry skin, fungal infections, dark velvety patches, and injection-site lumps are common and usually manageable; some are clues worth mentioning to your care team.

Action Points

1. Look today. Take off your shoes and socks now and inspect the soles, heels, tops, and between the toes, using a mirror or a helper.
2. Book a foot exam. If your feet have not been checked without shoes in the past year, ask for it at your next visit and ask for your risk category.
3. Check your shoes. Put your hand inside every pair you wear, and replace footwear that rubs, is too tight, or has a rough seam.
4. Plan for barefoot moments. Decide where you will keep house shoes, what you will wear to the beach or place of worship, and how you will check your feet afterwards.
5. Write your same-day list. Put your care team's number on the fridge, along with the signs that mean "call today": any break in the skin, redness, swelling, warmth, black skin, or fever.

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.