Most diabetic foot ulcers do not begin with an injury anyone noticed. They begin with a shoe that rubbed, a pebble that was not felt, a callus that cracked — in a foot that had lost the ability to report pain. That is why risk in the diabetic foot is assessed by what has been lost, not by how the foot looks or feels today.
In short: two things decide the risk category — whether protective sensation has been lost and whether the circulation is reduced. Foot deformity raises it further, and a previous ulcer or amputation places the foot in the highest category regardless of everything else. The international system (IWGDF) sets the review interval accordingly: once a year at one end, every one to three months at the other.
Diabetic foot risk check
Seven questions, applying the IWGDF categories. It runs in your browser and nothing is stored or sent anywhere.
This is a self-check. Reduced sensation and reduced circulation are confirmed by examination — a monofilament test and a pulse or pressure measurement — and both can be present without you noticing anything.
Why these two factors and not others
Lost protective sensation
Nerve damage from long-standing diabetes removes the warning system. The foot can be cut, burned, blistered or pressed against a seam for hours without the signal that would normally make you shift position or take the shoe off. People often describe it as numbness, but the more revealing sign is finding an injury you never felt happen. This is why the advice is always to look at the feet daily: in a neuropathic foot, looking replaces feeling.
Reduced circulation
Narrowed leg arteries mean less blood reaching the tissue, and a wound needs more blood to heal than intact skin needs to survive. A foot can therefore manage perfectly well at rest and fail to heal a small injury. Reduced circulation also limits how well antibiotics reach an infection, which is why opening the arteries comes before removing dead tissue in limb salvage. If walking brings on calf pain that stops when you stand still, the leg circulation self-check runs through that pattern.
A particular trap in diabetes: the ankle pressure measurement used to assess circulation can read falsely reassuring, because stiffened vessel walls resist compression. Toe pressures and waveform shapes are used instead. A normal-looking ankle reading in a diabetic foot should not close the question.
The risk categories, and what they mean in practice
| Category | What is present | Suggested review |
|---|---|---|
| 0 — very low | No loss of sensation and no reduced circulation | Once a year |
| 1 — low | Either loss of sensation or reduced circulation | Every 6 to 12 months |
| 2 — moderate | A combination: sensation loss with reduced circulation, or either with foot deformity | Every 3 to 6 months |
| 3 — high | Either of the above plus a previous ulcer, an amputation of any size, or end-stage kidney disease | Every 1 to 3 months |
Two features of this system are worth noticing. It is a decision tree, not a points total — a single high-weight finding moves the category rather than adding to a score. And a previous ulcer or amputation outranks almost everything: having had one foot ulcer is the strongest single predictor of having another, which is why that group is reviewed every few months for life rather than annually.
When an open wound changes the question
A risk category describes how likely an ulcer is. An ulcer that already exists is no longer a question of risk — it is a wound that needs treating, and the clock matters. A foot ulcer that is seen early is usually a manageable problem; the same ulcer weeks later, with infection and tissue loss, is a different situation with a different outcome.
Seek care the same day if a foot wound is accompanied by spreading redness, swelling, foul discharge, fever or shivering, if an area is turning black, or if the surrounding skin crackles when pressed. Go to an emergency department rather than waiting for an appointment. Seek care within days — not weeks — for any new ulcer, blister or crack that has not healed, however small it looks. And treat a foot that becomes suddenly cold, pale, numb and painful as an emergency: an artery may have blocked, and there is only a short window to reopen it.
What actually prevents ulcers
- Look every day — soles, heels and between the toes, using a mirror or a phone camera if you cannot see them easily. In a numb foot this is the whole early-warning system.
- Never walk barefoot, indoors or outdoors, and not in socks alone on hard floors.
- Check inside shoes with your hand before putting them on: grit, a seam, a folded insole.
- Do not cut calluses or corns yourself, and avoid over-the-counter corn removers — they are a recognised cause of ulcers in neuropathic feet.
- Moisturise dry skin daily, but not between the toes, where damp skin breaks down.
- Wear footwear that fits, with a wide toe box; where deformity has concentrated pressure, custom insoles or shoes genuinely reduce recurrence.
- Have anything unhealed at two weeks seen, and keep the scheduled reviews even when the feet feel fine — which, in a numb foot, they will.
Alongside these: glucose, blood pressure and cholesterol control, and stopping smoking. Smoking narrows exactly the small vessels the foot depends on, and in arterial disease of the legs nothing else available does as much for whether the limb is kept. Further detail is on the diabetic foot page and under diabetic foot and limb salvage.
Frequently Asked Questions
My feet feel fine — do I still need checking?
Yes, and this is the central point of the whole system. Loss of protective sensation is painless by definition, and reduced circulation often causes nothing until a wound fails to heal. Both are found by examination rather than by how the foot feels, which is why annual screening applies even in the lowest category.
How is loss of sensation actually tested?
Usually with a monofilament — a calibrated nylon strand pressed against defined points on the sole until it buckles. If you cannot feel it at those points, protective sensation is reduced. A tuning fork or a simple pinprick comparison may be used alongside it. It takes a few minutes and does not hurt.
Why does a previous ulcer matter so much years later?
Because the conditions that produced it — the neuropathy, the circulation, the pressure pattern — generally remain, and the healed site itself is more vulnerable than intact skin. Having had one foot ulcer is the single strongest predictor of having another, which is why that history alone places the foot in the highest category.
Is a normal ankle pressure reading reassuring in diabetes?
Not on its own. Long-standing diabetes and kidney disease stiffen the vessel walls, so they resist the cuff and the ankle reading can come out falsely high. Toe pressures and the shape of the Doppler waveform are used instead when this is suspected.
Can I treat a small callus or corn myself?
No. Cutting calluses, using corn plasters or over-the-counter removers is a well-recognised route to an ulcer in a foot with reduced sensation, because the damage is not felt. Callus should be reduced by a podiatrist, and recurring callus is itself a sign that pressure needs redistributing.
What is the single most useful habit?
Looking at your feet every day, including the soles and between the toes. It takes a minute, it requires nothing, and in a foot that cannot report pain it is the only early-warning system available.
Does good glucose control alone prevent foot ulcers?
It helps considerably over years by slowing nerve and vessel damage, but it does not remove the risk once sensation or circulation is already reduced. At that stage daily inspection, footwear and regular review are what prevent ulcers, and glucose control supports healing when something does happen.
Do you see international patients?
Yes. International and Gulf patients are seen in Istanbul with English- and Arabic-speaking support, and an initial remote assessment can be made from your existing reports and images before you travel.
References
- IWGDF 2023 — Guidelines on the prevention of foot ulcers in persons with diabetes
- IWGDF 2023 — Practical guidelines on prevention and management of diabetes-related foot disease
- NHS — Diabetes and foot problems
- MedlinePlus (NIH) — Diabetic foot
Related Pages
- Diabetic foot
- Diabetic foot and limb salvage
- Gangrene and limb salvage
- Peripheral artery disease (leg)
- Leg circulation self-check
- Second opinion and limb salvage
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This content is for information only and does not replace diagnosis or treatment. Assessment is made by a medical examination.
