Pressure ulcers (PrUs; also called

Pressure ulcers (PrUs; also called decubitus ulcers, pressure sores, and bedsores) are
localized areas of skin and soft tissue breakdown caused mainly by prolonged pressure,
friction, and shearing forces (i.e., parallel frictional force; e.g., skin adheres to bedding,
and bones with attached muscle tissue are pulled during movement), that can result in
ischemia, cell death, and tissue necrosis. PrUs may develop when immobility leads to
prolonged compression that reduces blood flow, usually between a bony prominence and a
hard surface.