Library · Disease
Pressure ulcer
Make it clearer
A pressure ulcer, also known as a bedsore, is an injury to the skin and to the soft tissue underneath. Two things cause it together and over time: pressure and shear, which is one layer being dragged across another. It typically appears over a bony prominence, that is, where the bone stands out under the skin, or under an object that presses from outside.
The tissue is crushed between a surface on the outside and bone on the inside. When that pressure exceeds the pressure needed to fill the capillaries, the capillaries and the lymphatic vessels close off. Without blood there is ischemia, and the cells die.
Something here fools the eye. The damage spreads in the shape of a cone, and the deformation and shear are greatest deep down, where the muscle rests against the bone. The damage can start next to the bone and reach the surface late, so there can be dead tissue inside while the skin on top still looks intact.
In brief
A pressure ulcer is an injury to skin and soft tissue from prolonged pressure and shear, typically over a bony prominence or under an external object.
Sustained compression exceeds capillary filling pressure, occludes capillaries and lymphatics, and the resulting ischemia kills cells.
The damage spreads in a cone, with deformation and shear highest at the deep bone-muscle interface, and deep necrosis can precede any visible breakdown.
The damage can start next to the bone and reach the surface late.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPressure Injury, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated