Erythema: A result of injury or irritation that causes dilation of blood capillaries and manifests as patchy reddening of the skin. Occurs after a patient/resident is exposed to unrelieved pressure for 2 hours. It can be identified as a deep, localized redness; can also be blue or purple.
Hyperemia: The condition of having excess blood in vessels that supply an organ or area of the body. Occurs after patient/resident is exposed to 30 minutes of unrelieved pressure. It can be identified as a localized, non-blanchable redness.
Perfusion: The passage of blood through arteries and capillaries into tissues or organs. When insufficient, there is an increased chance that the patient may have complications.