5 min read
Most foot problems announce themselves. They hurt, and the pain is what sends someone looking for answers. Diabetes can remove that signal. When the nerves carrying sensation from the feet are affected, an injury can sit for days without registering, and the first sign of trouble is something noticed by eye rather than felt. That is the reason feet get their own appointment in diabetes care, separate from everything else.
What diabetes changes in the foot
Two systems are involved. They are separate problems, and they often show up together.
The first is the nerves. Over time, elevated blood sugar can damage the small nerves running to the feet, a condition called peripheral neuropathy. It usually begins in the toes and works upward, and it tends to affect both feet in a similar pattern. People describe it as numbness, pins and needles, burning, or a sense of walking on a thick sock that is not there.
The second is circulation. The same process can narrow the vessels supplying the lower leg and foot. Less blood reaching the tissue means less of what the body needs to repair itself, which is why a break in the skin that would be unremarkable elsewhere can behave very differently here.
What neuropathy feels like varies more than people expect:
- Numbness, or a dulled sense of touch that makes it hard to tell hot from warm.
- Pins and needles, tingling, or burning, often more noticeable at night.
- A feeling of walking on padding, or on uneven ground that is actually flat.
- No symptom at all. Sensation can be measurably reduced without ever feeling strange, which is why protective sensation is tested rather than asked about.
Why a small sore is treated as a bigger deal here
Put the two changes together and an ordinary sequence of events takes on a different character. A shoe rubs. A pebble sits in a sock for an afternoon. A toenail is cut slightly too short. None of it hurts, so none of it prompts a look.
By the time the spot is seen, it may already be an open wound rather than a red mark, and the reduced circulation that allowed it to get there is the same reduced circulation that slows it closing. This is what is meant by a diabetic foot ulcer. It is not an exotic injury. It is an ordinary one that went unnoticed and did not heal on the usual schedule.
It is also why the guidance around diabetic feet can sound out of proportion to the size of the problem. The concern is not the sore. It is what an open wound on a foot with reduced sensation and reduced blood supply can become, and the fact that the person carrying it may feel none of it happening. The great majority of amputations related to diabetes are preceded by a foot ulcer, and that is the stage where attention is aimed.
Changes that warrant a call rather than a wait
With sensation reduced, the eye has to do the work the nerves would normally do. These are the changes that generally prompt a call within the week rather than a period of watching. The last two on this list are worth naming because they are the easiest to dismiss: a foot that changes shape, or one that becomes hot and swollen with no injury behind it, is not a normal part of living with diabetes and is looked at promptly.
- Any open area, blister, crack, or sore, however small, and whether or not it hurts.
- Redness, warmth, or swelling in one area, particularly on one foot and not the other.
- Drainage, odor, or staining inside a sock with no obvious explanation.
- A callus that darkens or develops a spot within it, which can indicate damage beneath the surface.
- A foot that changes shape, or becomes warm and swollen with no injury to account for it.
- New numbness, new burning, or any change in what the feet have been feeling.
What a diabetic foot evaluation involves
A foot exam for someone with diabetes is a specific set of checks rather than a general look, and it is recommended at least once a year even when nothing appears wrong, more often once the feet have already shown changes. It usually covers:
- Sensation. A thin nylon filament is pressed against several points on the sole until it bends. Whether it is felt is a standard way of measuring protective sensation. Vibration sense and reflexes may be checked alongside it.
- Circulation. Pulses in the foot and ankle are felt for, and the temperature, color, and hair growth of the skin are noted. Where there is a question, pressure at the ankle can be compared with pressure in the arm.
- Skin and nails. The whole foot is inspected, including between the toes and the back of the heel, the two places people cannot easily see on themselves.
- Structure and pressure. Where the foot is taking load, and whether calluses are building in places that suggest a pressure point.
- Footwear. The shoes are often examined directly, along with what is inside them.
If you have diabetes and have not had your feet examined within the past year, or you have noticed something on a foot you cannot account for, that is reason enough to book. Our Chillicothe office performs diabetic foot evaluations and treats wounds of the foot and ankle.
This article is general information about a common foot and ankle condition. It is not medical advice and it is not a diagnosis of your own symptoms. If something is wrong with your foot, have it examined.
Care at Bends Foot and Ankle is provided by Eric Storts, DPM, FACFAS, board certified podiatric foot and ankle surgeon.