Callus is the bodies defense mechanism. When there is friction over a particular are of the foot the body will form diffused yellow hardening of skin to protect the area. However in doing so it can in fact cause more pressure and pain if too much forms.
Callus on the feet is known as ‘plantar callus’ or hyperkeratosis which can become quite painful, resulting in healthy tissue breakdown and underlying wounds.
If darkened areas or bruising start to form under the hardened skin, this is a sign that there is too much pressure. This will need to be removed by a podiatrist to prevent further complications and foot pain.