We have all heard these terms discussed by nurses, family members and in the media. Is there a difference? The answer is no. All of these terms refer to the same condition which occurs when pressure is exerted on the skin, soft tissue, muscle, and bone by the weight of an individual against a surface beneath. These pressures are often in excess of capillary filling pressure, (the pressure it takes to fill small blood veins). In patients with normal sensitivity, mobility, and mental faculty, pressure sores do not occur. Feedback, both conscious and unconscious, from the areas of compression leads individuals to change body position or move.
Many factors contribute to the development of pressure sores, but pressure leading to ischemia (or lack of oxygen) is the common cause. Tissues are capable of withstanding enormous pressures when brief in duration, but prolonged exposure to pressures slightly above capillary filling pressure initiates a downward spiral towards ulceration.
Impaired mobility is an important contributing factor. Patients who are neurologically impaired, heavily sedated, restrained, or demented are incapable of assuming the responsibility of altering their position to relieve pressure. Moreover, this paralysis leads to muscle and soft tissue atrophy, decreasing the bulk over which these bony prominences are supported.
Read a more detailed explanation in this article from WebMD.
My next post will discuss ways to avoid pressure sores or decubitus ulcers.