If the skin is exposed to an intermittent pressure for a long time it may thicken. The build-up of skin that gradually hardens and gets yellowish color is also known as corn. Corns usually appear on the hands and feet, but they may appear on other body parts as well.
Calluses are special forms of corns, they are bigger and more painful and their roots are deep in the skin. People that have calluses usually feel pain during walking and feel very uncomfortable.
Prevention and proper hygiene:
Corns that appear on the hands are difficult to prevent if you have a hard physical job, but calluses can be avoided by wearing comfortable shoes. If you have painful calluses you should have a pedicure for medical purposes and get rid of them. Also, you can go to a doctor, but never try to remove them on your own.
A powerful cure for corns and calluses is chopped garlic soaked in olive or almond oil. Moreover, poultices of cabbage leaves or onion are effective and have calming properties as well.
Treatments with healing herbs:

rub the painful spot with fresh fig leaves.

apply poultices of smashed houseleek leaves on the painful spot.

make an ointment of two ivy leaves boiled in a liter of red wine or strong vinegar and apply it on the painful spot.

make calendula tea (five pinches in a liter of water) and apply it on the affected area. Also, you can apply fresh calendula leaves or garlic.

if you have callus you can treat it with celandine juice.
The best recipe:
Buy comfortable shoes!