Bedsores are ulcers that happen on areas of the skin that are under pressure from lying in bed, sitting in a wheelchair, or wearing a cast for a prolonged time. Bedsores are also called pressure injuries, pressure sores, pressure ulcers, or decubitus ulcers. Bedsores can be a serious problem among frail older adults.
https://www.hopkinsmedicine.org/health/conditions-and-diseases/bedsores