The general principle is simple: the less your foot can feel, the lower the threshold should be. Pain is the body's alarm. Where the alarm has been disconnected — by diabetes, by neuropathy from any cause, by reduced circulation — the absence of pain means nothing at all, and decisions have to be made by looking rather than by feeling.
Seek urgent same-day assessment
These warrant emergency or urgent care rather than an appointment in a few days:
- A foot that has suddenly become cold, pale, blue or mottled, particularly with new severe pain. This can indicate an interrupted blood supply and is time-critical.
- Spreading redness, heat or swelling extending up the foot or leg from a wound, blister or nail, especially with fever, shivering or feeling generally unwell. This suggests spreading infection.
- A wound with foul-smelling discharge, blackened tissue, or an area of skin that has turned dark.
- A deep puncture wound — standing on a nail, a spine or broken glass — particularly through a shoe, which drives contaminated material deep into the tissues.
- An injury after which you cannot bear weight, or where the foot or ankle is visibly deformed, or where there is bone tenderness after a fall or twist.
- A single joint, most often at the base of the big toe, that has become suddenly extremely painful, hot, red and swollen over hours. This needs distinguishing between acute gout and joint infection, and the second is an emergency.
- New numbness, weakness or inability to lift the foot, or numbness affecting both feet that is ascending.
- Any new break in the skin of the foot in a person with diabetes. This is the one that is most often left too long and matters most.
Arrange an appointment soon — within days to a couple of weeks
- Foot pain that has persisted beyond two to three weeks despite rest, sensible footwear and simple measures.
- Pain that is changing the way you walk, since a compensating gait creates its own problems further up the leg.
- An ulcer, crack or graze that is not clearly closing, in anyone.
- An ingrown toenail with surrounding redness, swelling or discharge.
- A nail that has changed colour, thickness or shape and is not growing out; particularly a single dark or pigmented streak in one nail, which should always be looked at.
- Numbness, pins and needles, burning or night pain in the feet, whether or not you have a diabetes diagnosis — this is sometimes how diabetes is first found.
- Cramping pain in the calf or foot that comes on reliably after walking a certain distance and is relieved by rest, which may indicate arterial disease.
- A lump, swelling or area of thickening that is growing.
- Swelling of one foot or ankle without an obvious cause, particularly if one side is affected and the other is not.
- A toe or forefoot that is visibly changing shape, drifting or riding over its neighbour.
- Recurrent falls or a new sense of instability on the feet.
- Any foot concern at all if you have diabetes, peripheral arterial disease, rheumatoid arthritis, a previous foot ulcer, a previous amputation, or you are on medication that suppresses the immune system.
Reasonable to watch for a short period
A simple blister on an intact, well-perfused foot with normal sensation. Mild aching after unusual activity. A single small callus that is not painful. Athlete's foot responding to over-the-counter treatment. A minor graze that is closing normally.
"Watch" means genuinely watch — check it daily, and act if it is not clearly improving within a week or two, or at any point if it worsens. It does not mean forget about it for two months.
If you have diabetes, the rules are different
Nothing in the "watch and wait" paragraph above applies. A blister, a small cut, a crack in the heel, a corn, a colour change, a warm patch or a stain on a sock all warrant contact with your foot care service the same day or the next. This is not caution for its own sake: foot ulceration precedes the great majority of diabetes-related amputations, and the strongest single determinant of outcome is how quickly a wound is assessed. Both the National Institute of Diabetes and Digestive and Kidney Diseases and Diabetes UK set out the same message.
What to bring to the appointment
The shoes you wear most, including the ones you were wearing when the problem started — they carry a great deal of diagnostic information in their wear pattern and their fit. A note of when the problem began, what makes it better and worse, and what you have already tried. A list of your medications and medical conditions, including any diabetes, circulatory or inflammatory diagnoses. And, if you use them, your current insoles or orthoses.
A closing caution about this page
A list of red flags is a prompt to seek assessment, not a way to rule anything out. Symptoms that are absent from this page are not thereby safe, and a symptom you cannot categorise is a reason to ask rather than a reason to wait. If you are uncertain, that uncertainty is itself the answer: have it looked at.
Further reading on this site: the condition index, the diabetic foot, and preparing for a foot and ankle appointment.