How They Develop
People with normal mobility do not develop pressure ulcers, as their body automatically makes hundreds of regular movements that prevent pressure building up on any part of their body.
For example, while you are asleep you may think you are lying still, but you may shift position up to 20 times a night. Pressure ulcers can develop when a large amount of pressure is applied to an area of skin over a short period of time. They can also occur when less pressure is applied over a longer period of time. The extra pressure disrupts the flow of blood through the skin. Without a blood supply, the affected skin becomes starved of oxygen and nutrients and begins to break down, leading to an ulcer forming.
The lack of blood supply also means that the skin no longer receives infection-fighting white blood cells. Once an ulcer has developed, it can become infected by bacteria. Conditions that affect the flow of blood through the body, such as type 2 diabetes, can also make a person more vulnerable to pressure ulcers.
Pressure ulcers can be caused by:
- Pressure from a hard surface, such as a bed or wheelchair.
- Pressure that is placed on the skin through involuntary muscle movements, such as muscle spasms.
- Moisture, which can break down the outer layer of the skin (epidermis).