Pressure sores

Also known as "pressure sores" or "bed sores", pressure ulcers are injuries to the skin and underlying soft tissue caused by an interruption in blood supply to the area. This interruption is caused by pressure when sitting or lying in one position without moving. The pressure of our bones against a hard surface presses the soft tissue in between - with or without movement. The blood vessels which supply this tissue are also pressed so that less blood can reach the area. If the blood supply is restricted over time the cells of the tissue begin to die. The pressure sore may first appear as a darkened patch of skin which does not disappear when pressed with the tip of the finger (non-blanching erythema). This may indicate deeper skin damage.

Depending on the amount of pressure and the hardness of the surface, pressure sores can take minutes or a couple of hours to develop and become worse over time. They develop more quickly on hard surfaces and more slowly on soft surface like beds.