Furunkul võib esineda mis tahes karvadega kaetud kehaosal, sagedamini aga rohkete rasunäärmetega piirkonnas, mida riided tihedalt pitsitavad, nagu kukal, kael, selg, puusad ja tuharad. Tekitajaks on üldjuhul kobarkokk (stafülokokk).
In most cases a single boil is not serious and will respond to incision and drainage. Systemic antibiotics are also sometimes indicated. Although complications are rare, a boil on or above the upper lip, on the nose or scalp, or in the outer ear can be serious because in these areas infection has easy access to the brain. Other danger zones are the armpit, the groin, and the breast of a woman who is nursing. If bacteria from a boil enter the bloodstream, septicemia may result.
