Pressure sore

also called a pressure ulcer, bedsore, and decubitus ulcer. An injury to the skin, and sometimes to the tissue underneath, caused by lack of blood circulation. Pressure sores are classified by “stages,” or degrees of severity. A stage 1 pressure sore is a reddened area that stays red after pressure has been removed half to three-fourths of the time that pressure was applied. For example, if the resident was seated for an hour, the redness remains after 30 to 45 minutes. (For people with dark skin, a stage 1 pressure sore is diagnosed when the skin is grayish, warm, swollen or tender.) Also, a stage 1 pressure sore is nonblanchable: that is, it stays red when pressure is reapplied. A stage 2 pressure sore has a partial loss of skin thickness, from an abrasion, blister or shallow crater. A stage 3 pressure sore is complete missing some skin, with the tissue underneath exposed. A stage 4 pressure sore has both skin and tissue missing, with muscle or bone exposed.