X-rays will often be taken to identify the specific bone problem that is causing the corn or callus. The finished x-ray will then show the location of the corn and the bone spur underneath that caused it. The skin thickens in response to this pressure, in order to keep you from getting an open sore or blister. Small amounts of friction or pressure over long periods of time cause a corn or callus. Large amounts of friction or pressure over shorter periods of time cause blisters or open sores.
Corns can be due to a buckled or contracted toe position called a hammer toe.
Many of these bone conditions are inherited. Trimming of this thick skin can relieve the pressure for a short time. You should never consider doing this yourself if you are diabetic or have poor circulation. If you cut yourself, you may cause an infection. You can begin by soaking your feet in warm soapy water and gently rubbing away any dead skin that loosens.