The hard areas on your feet that can become quite painful if not treated are called Corns and Callus.
A corn is generally smaller than callus. Like callus they are hard but a corn has a central core that has been pushed into the skin. They are often found over a bony prominence like the top of a toe or under the ball of your foot. They are the ones that seem like there is a seed stuck in your foot. There are several types of corns all with different attributes. The technical terms are Heloma Durum, (larger hard corn), Heloma Mole (soft corn) and Heloma Millare (small hard corns).
Callus can be found on any weight bearing part of the skin. They cover a larger area of the skin than corns do. Cracked heels is callus that has become dry and fissures. The technical term for callus is Hyerkeratosis.
The growth of hard skin is a normal response from the body. It occurs when the skin is under an increased amount of force. Certain layers of skin will produce more skin cells. This makes it thicker to create a protective shield against the area of skin under pressure. If it grows too much it can become painful and even lead to breakdown of the tissue under the hard skin if not addressed.
Footwear is the leading cause of corn and callus development along with your foot type. If the shoe you are wearing is too tight or too loose in any area, the skin can respond by growing a corn or callus. Narrow fitting shoes are the most common culprit. Your foot anatomy and biomechanics (the way you move) are also major contributors to the development of a corn or callus. A common site for callus is along the inside of the big toe joint. This is a sign the foot is propelling off the inside of the toe and the big toe joint isn’t functioning efficiently. In combination with footwear compressing on the inside if the big toe, the callus will develop.
Podiatrists are trained in the removal of corns and callus using a scalpel. It is a very effective way of relieving pain and discomfort. Along with the physical removal of the corn or callus, looking at what forces are being applied to lead to the hard to grow is addressed. This can be done through footwear modification or change, offloading the area with padding or even orthotic therapy. If the force being applied to the foot can be reduced, the growth of the corn or callus can cease.