Abscess, << AB sehs, >> is a collection of pus within an infected part of the body. Pus contains bacteria, blood plasma, and debris from dead cells. It also contains white blood cells, which the body uses to combat infection. An abscess often appears as a red and swollen lump, which may open and drain. Abscesses may occur in any tissue that becomes infected by bacteria.
When abscesses form, blood vessels dilate (expand) and fluid from the blood collects in the injured tissue. Serum and white blood cells help destroy the invading bacteria and their poisons. Abscesses swell because the blood vessels expand and the amount of blood in the infected area increases. An abscess is painful because the pus presses on the nerve endings.
Small superficial abscesses, such as pimples, need no special treatment. Boils, carbuncles, or internal abscesses are treated with antibiotics, such as penicillin, and surgical incision if necessary (see Antibiotic ). An abscess at the root of a tooth should be treated by a dentist. No abscess, regardless of size, should be squeezed, because bacteria can enter the bloodstream and produce infection elsewhere.
