Blog · Boston Limb
Why Diabetic Foot Ulcers Sometimes Fail to Heal
A dressing treats the surface of a wound. When a diabetic foot ulcer stays open for weeks despite careful dressing, the problem is almost never the dressing. It is one or more of six things underneath, and they are usually found together.
1. Blood sugar that stays high
Raised glucose slows every stage of healing: the immune cells that clear bacteria work less well, new tissue forms more slowly, and the small blood vessels that bring oxygen to the wound edge are damaged. A wound in a person whose sugars run high is trying to heal with the brakes on.
2. Pressure landing on the same spot
Most diabetic foot ulcers sit under a bony prominence: the ball of the foot, the tip of a toe, the heel. Every step presses the wound closed and then tears it open again. No amount of dressing can compete with that, which is why offloading, the deliberate removal of pressure from the wound with footwear, insoles, padding or a walking boot, is often the single most important part of treatment.
3. Reduced blood flow to the foot
Diabetes narrows the arteries of the legs, often silently. A wound needs oxygen and nutrients delivered through those arteries; when the supply is poor, healing stalls no matter what is done at the surface. Checking the pulses, the temperature and the colour of the foot is part of every assessment, and when blood flow is in doubt, vascular imaging and a vascular specialist are brought in.
4. Infection in or under the wound
Infection can be obvious, with redness, swelling, discharge and smell, or quiet, with a wound that simply refuses to close. Neuropathy hides the pain that would normally raise the alarm. Deep infection can reach bone. Finding and treating infection early changes the course of a diabetic foot ulcer more than almost anything else.
5. Kidney disease and other illness
Diabetic kidney disease, anaemia, poor nutrition and some medicines all slow healing. They are easy to miss when attention is on the wound itself, which is why a nephrologist and a physician review the whole picture alongside the wound care.
6. Footwear that rubs or does not fit
A surprising number of ulcers begin with a shoe. Hard seams, tight toe boxes, worn insoles and sandals that let the foot slide all create friction on skin that cannot feel it. The shoes worn most are examined as carefully as the foot.
Why they are usually found together
High sugars damage the nerves and the arteries at the same time. Damaged nerves let pressure and friction go unnoticed; poor circulation starves the wound; infection takes hold in tissue that cannot defend itself. A wound that will not heal is usually a wound with two or three of these problems acting at once, which is why treating any one of them alone so often disappoints.
What a complete assessment looks for
- The wound itself: size, depth, location, duration, the skin around it, signs of infection, and what has been tried
- Sensation and protective sensation, with nerve conduction testing where it adds information
- Circulation: pulses, skin temperature and colour, with vascular imaging when indicated
- Blood sugar control, the medicines being taken, and kidney function
- The footwear and the pattern of pressure on the foot
From that comes a written plan: wound care, offloading, treatment of infection where it is found, adjustment of diabetes and kidney medicines, foot-care education, and coordination with vascular or surgical specialists when a blocked artery, deep infection or surgery needs their care. Those procedures are referred, not performed at the clinic.
The short version
If a foot wound has been open for two weeks, or keeps coming back in the same place, it has already shown that a dressing alone is not enough. The next step is an assessment that looks at all six causes in one visit.
Book a Foot and Nerve Evaluation
One visit assesses the wound, the nerves, the circulation and the diabetes behind them, with FDA-cleared DPNCheck nerve testing on site. Gachibowli, Hyderabad. Mon to Sat, 10:00 AM to 8:00 PM.
Related reading
Burning Feet at Night: Could It Be Diabetic Neuropathy?
Why burning, tingling or numb feet are often noticed at night, and why they deserve a proper evaluation.
What Is DPNCheck? Understanding a Test for Diabetic Nerve Health
What the test measures, what to expect, and how the result fits into a wider evaluation.
Written by the Boston Limb care team. The information in this article is general and does not replace an individual consultation or teleconsultation. Assessment and treatment depend on clinical evaluation, and outcomes vary.