Diabetic Foot Ulcers: Causes, Warning Signs and Prevention

Diabetic foot ulcer (DFU) is one of the most serious late complications of diabetes. The IWGDF estimates a lifetime incidence of 19–34% in people with diabetes; DFUs are the leading cause of non-traumatic lower-limb amputation worldwide.

Why is the diabetic foot vulnerable?

Three mechanisms converge on the diabetic foot: peripheral neuropathy, peripheral artery disease (PAD), and impaired immune response. Neuropathy means the patient cannot feel pressure or trauma; reduced arterial flow impairs oxygen delivery; immune impairment makes minor injuries more likely to become infected.

Major risk factors

• Previous ulcer or amputation
• Loss of protective sensation (10 g monofilament test)
• Peripheral artery disease (absent pulses, abnormal ankle-brachial index)
• Foot deformity (hallux valgus, claw toe, Charcot foot)
• Poor glycaemic control (HbA1c > 8%)
• Chronic kidney disease, especially on dialysis
• Visual impairment or limited mobility

Daily prevention checklist

1. Inspect the entire foot every day, including between the toes.
2. Wash with lukewarm (not hot) water and dry carefully.
3. Moisturise the dorsum and sole — never between the toes.
4. Cut nails straight, never below the nail bed.
5. Never walk barefoot, even at home.
6. Inspect inside shoes before wearing.
7. Wear seamless, properly fitted footwear with appropriate insoles.
8. Avoid hot water bottles and electric heaters near the feet.
9. See a wound specialist within 24 hours of any new lesion.

Glycaemic, blood pressure and lipid control

DCCT and UKPDS demonstrated that each 1% reduction in HbA1c reduces microvascular complications (including neuropathy) by roughly 21%. Blood pressure below 130/80 mmHg, individualised LDL targets and complete smoking cessation all lower amputation risk.

When to seek urgent care

Any new wound on the diabetic foot — however small — is a clinical emergency. A delay of even a few days can convert a superficial ulcer into osteomyelitis. Refer the patient to a specialist wound centre at the earliest opportunity.

References

1. Bus SA, Lavery LA, Monteiro-Soares M, et al. IWGDF 2023 Guidelines on the prevention of foot ulcers in persons with diabetes. Diabetes Metab Res Rev. 2024;40(3):e3651. https://iwgdfguidelines.org/
2. American Diabetes Association. Standards of Care in Diabetes—2024. Diabetes Care. 2024;47(Suppl 1). https://doi.org/10.2337/dc24-S012
3. Armstrong DG, Boulton AJM, Bus SA. Diabetic Foot Ulcers and Their Recurrence. N Engl J Med. 2017;376(24):2367–2375. https://doi.org/10.1056/NEJMra1615439