An abscess is a sore place in the body where an infection has made a pocket of thick yellowish liquid. That liquid is pus. The spot is often red, hot, swollen, and it hurts in a deep, beating way. It can sit under the skin, in the gum beside a bad tooth, or deeper inside — a doctor may talk about an abscess in the liver or even the brain. The body is trying to wall the germs off. Though actually, that wall is not a happy ending: the pocket can grow, burst, or make you very ill if it is not treated. People sometimes wait, hoping it is “just a spot,” but an abscess is not a normal pimple. A pimple is small and usually stays in the skin; an abscess is an infection with a collection of pus, and it often needs a doctor — sometimes to drain it, often with medicine. You will hear the word at the dentist and in hospitals. It is medical, but not rare.