Skin concerns
When a callus is painful or inflamed
A plain callus does not hurt. Pain, redness, warmth or a dark spot underneath means something else is going on, and some of it needs same-week care.
- Painless and broadOrdinary callus, relieve the pressure
- Painful or warmInfection, ulcer or wart underneath
- Diabetes changes itNo acid plasters, get it looked at
On this pageWhat an ordinary callus is doing5
Quick answer
The bottom line
Treat pain as the signal. Ordinary calluses are painless pads of thickened skin that form where pressure repeats, and they respond to removing the pressure plus urea or salicylic acid softening. Pain, redness, warmth, pus or a dark patch under the thickened skin means it is no longer an ordinary callus: an ulcer underneath, an infection, a wart or a trapped foreign body all present that way. Anyone with diabetes, nerve damage or poor circulation should skip the medicated pads entirely and be seen. Never cut one yourself.
At a glance
Three things worth remembering
Section 01
What an ordinary callus is doing
Skin thickens where pressure or rubbing repeats. That is protective, and on the ball of the foot, the heel, a palm or an elbow it is the body working correctly. The pad is broad, evenly thickened, the same colour as surrounding skin, and it does not hurt when you press it.[1][2]
A corn is the same process concentrated into a small area, usually with a firmer centre, and it can be tender under direct pressure because that centre presses inward. Tenderness on a corn is expected. Genuine pain in a broad callus is not.[1][2]
Section 02
What pain, redness or a dark spot means
Redness spreading beyond the thickened area, warmth, swelling, pus or a bad smell point to infection and need same-week medical care. Skin that has broken under the callus can be infected without looking dramatic from the outside, particularly if sensation is reduced.[1][4]
A dark red, brown or black patch showing through thickened skin is usually blood that has collected underneath. In someone with diabetes or reduced sensation, dermatology and foot-care guidance treat that as an early ulcer until proven otherwise, and it is a reason to be seen rather than to file it down at home.[4][1]
Section 03
When it was never a callus
A plantar wart is often mistaken for a callus. The giveaway is that it hurts when squeezed from the sides rather than pressed straight down, it may show tiny dark dots, and skin lines bend around it instead of running through it. It is a viral infection and needs different treatment.[6][1]
A splinter, a shard of glass or a small stone driven into the sole builds thickened skin over itself and hurts in one exact spot. So can a stress fracture or a nerve problem, neither of which improves with anything applied to the surface. Pain in one precise point that does not shift with different shoes is worth an examination.[1][4]
Section 04
What is safe to do at home
Take the pressure off first, because nothing else holds without it: wider or deeper shoes, a proper insole, padding around rather than on top of the spot, and gloves or a pad for hands and elbows. Softening the skin without changing the pressure means the callus returns in weeks.[2][1]
Soak, then use a urea cream at 20 to 40 percent daily, or a salicylic acid product on the thickened area only. Rub gently with a pumice after soaking. Do not cut, shave or scrape with a blade: the wound underneath is worse than the callus, and it can become infected.[5][3]
Section 05
Who should not treat this at home
Diabetes, peripheral neuropathy, peripheral arterial disease or any condition that reduces sensation or blood flow in the feet changes the calculation completely. Medicated corn plasters and acid products can burn skin that cannot feel it, and product labels carry that warning for exactly this reason.[3][2]
In that situation the right step is a podiatrist or your usual clinician, who can pare the callus safely, look for what is underneath and sort out the pressure. Routine foot checks catch these before they open, which is the whole point of doing it that way.[4][1]
Your next step
Turn this into a practical plan
Choose the guide that best matches what you see. Each one starts with what to try, how long to wait and when to get help.