Bedsores occur when elderly or disabled people lay in one position for too long. That’s because laying in one position for more than three hours can cut off blood flow to the skin. Without adequate blood flow, the skin tissue begins to die, therefore creating a pressure ulcer. For example, if a bedbound person lays on their back for more than three hours every day, they could begin developing bedsores on their tailbone, elbows, shoulders, back of the head, etc.