A pressure sore is an area of skin breakdown that begins as redness and inflammation on the skin surface and can progress to death, pussy skin that must be surgically debrided (cut off). The most common site for a pressure sore is the buttocks or sacrum. Pressure sores develop as a result of unrelieved pressure on the affected part of the body. For example, if a nursing home resident is immobile and he/she is not able to move, the weight of the resident’s body places pressure on their buttocks and sacrum.