A boil, also known as a furuncle, is a swollen, pus-filled growth on the skin that occurs when bacteria—even those normally found on your body—infect a group of hair follicles. Boils commonly develop ...

A brain abscess is a localized collection of pus in the brain, often resulting from infections in nearby areas like the sinuses or ears. The classic triad of symptoms—fever, headache, and focal ...