An abscess is a collection of pus in any part of the body that, in most cases, causes swelling and inflammation around it.

Abscesses occur when an area of tissue becomes infected and the body's immune system tries to fight it. White blood cells move through the walls of the blood vessels into the area of the infection and collect within the damaged tissue. During this process, pus forms. Pus is the buildup of fluid, living and dead white blood cells, dead tissue, and bacteria or other foreign substances.

Abscesses can form in almost any part of the body. The skin, under the skin, and the teeth are the most common sites. Abscesses may be caused by bacteria, parasites, and foreign substances.

Abscesses in the skin are easy to see. They are red, raised, and painful. Abscesses in other areas of the body may not be obvious, but they may cause significant organ damage.

Some specific type of abscesses are:

• Abdominal abscess
• Amebic liver abscess
• Anorectal abscess
• Bartholin's abscess
• Brain abscess
• Epidural abscess
• Peritonsillar abscess
• Pyogenic liver abscess
• Skin abscess
• Spinal cord abscess
• Subcutaneous abscess
• Tooth abscess

Often, a sample of fluid will be taken from the abscess and tested to see what organism is causing the problem.

Treatment varies, but often surgery, antibiotics, or both are needed.

Call your health care provider if you think that you may have any type of abscess.

Prevention of abscesses depends on where they develop. For example, good hygiene can help prevent skin abscesses. Dental hygiene and routine care will prevent tooth abscesses.

Bolognia J. Infections, hyper- and hypopigmentation, regional dermatology, and distinctive lesions in black skin. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 467.