On this Wikipedia the language links are at the top of the page across from the boil then grill ribs title. This article is about the contagious skin disease. For the change in state from liquid to gas, see Boiling.

A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. Boils are bumpy, red, pus-filled lumps around a hair follicle that are tender, warm, and painful. They range from pea-sized to golf ball-sized. A yellow or white point at the center of the lump can be seen when the boil is ready to drain or discharge pus. Boils may appear on the buttocks or near the anus, the back, the neck, the stomach, the chest, the arms or legs, or even in the ear canal. Boils may also appear around the eye, where they are called styes. When a boil bursts, a seemingly solid, whitish colored pus initially appears then the pus and some blood follows.

Naturally the cause is bacteria such as staphylococci that are present on the skin. Bacterial colonisation begins in the hair follicles and can cause local cellulitis and inflammation. Diagnosis is made through clinical evaluation by a physician, which may include culturing of the lesion. A boil may clear up on its own without bursting, but more often it will need to be opened and drained. This will usually happen spontaneously within two weeks. Regular application of a warm moist compress, both before and after a boil opens, can help speed healing.