A corn is your skin protecting itself. Pressure or rubbing on one spot — usually from shoes, or from the way you walk — makes the skin pile up extra layers. Take the pressure away and the corn goes away. Corns only form where there is pressure, so they show up on the ball of the foot, the heel, or the sides and tops of toes.
A plantar wart is an infection. It comes from HPV, a common virus you pick up through tiny breaks in the skin — often on wet floors like pool decks, locker rooms, and shared showers. Because it is a virus and not a pressure problem, a wart can appear anywhere on the sole, including places that take no weight at all.
That last point is one of the most useful clues. A thick spot in a no-pressure area is very unlikely to be a corn.
1. Look at the skin lines.
Your sole has fine lines on it, like fingerprints. On a corn, those lines run straight over the top of the bump. On a wart, the lines stop at the edge and go around it. The virus disrupts the skin's normal architecture, so the lines cannot pass through.
This is the single most reliable thing you can check at home.
2. Look for black dots.
Warts often have tiny black or dark brown pinpoints in them. People call them "seeds," but they are not seeds — they are small clotted blood vessels feeding the wart. A corn has no black dots. Instead, if you look closely at the centre of a corn, you may see a hard, slightly see-through core.
3. Squeeze it sideways.
Press straight down on the spot, then pinch it from the sides.
A callus is the same idea as a corn, just spread out. A corn is small, deep and has a core. A callus is a broad, flat patch of thickened skin with no core, and usually does not hurt much.
Think of it as: callus is a wide layer, corn is a concentrated point, wart is a virus.
Different thing entirely. A bunion is a bony bump at the base of the big toe, where the joint has shifted out of line. It is a bone and joint problem, not a skin problem. You cannot pare it down or treat it with acid.
Corns often form on top of a bunion, though, because the bump rubs against the shoe. If you have a painful bump at the big toe joint, that is a podiatry or orthopedic question.
Corns. The treatment is taking the pressure off. Shoes with a wider toe box, cushioned insoles, and padding around the corn. A dermatologist or podiatrist can pare the thickened skin down, which relieves pain right away. Softening creams with urea or salicylic acid help. But if the pressure stays, the corn comes back — so the shoes matter more than the cream.
Plantar warts. Salicylic acid is the usual first step, at much higher strengths than a corn pad. Soak the foot, file the surface gently, apply, cover, and repeat daily. It takes patience — often two to three months. In the clinic, freezing with liquid nitrogen every one to two weeks is common, and other options include cantharidin or in-office treatments for stubborn cases. About 70% clear with consistent treatment over several months.
Warts also go away on their own eventually, as your immune system catches up. That takes longer in adults than in children.
That last one matters. Reduced sensation or blood flow in the feet turns a small skin problem into a serious one quickly.