A lesion is an injury to the living tissue on your body, like your skin or an organ. Usually a lesion involves a break or wound to the skin, so protect it with a bandage so that it heals quickly.
Lesion, pronounced "LEE-zhun," comes from the Latin word laesionem meaning "injury." Lesions on the skin are usually not very nice to look at, the kind of wounds that might make you grimace — things like open sores, cuts, deep scrapes or puss-filled gashes. Lesions also are a concern of doctors because if lesions develop without explanation, it can be a sign that your immune system is dangerously weak.