Blackheads are one of the most common manifestations of acne, and they will most often occur in the chin and nose. Although people who have oily skin or acne-prone skin are more likely to have blackheads, anyone can have them.
Blackheads form when a clog or plug develops in the opening of hair follicles in your skin. Each follicle contains one hair and a sebaceous gland that produces oil. This oil, called sebum, helps keep your skin soft. Dead skin cells and oils collect in the opening to the skin follicle, producing a bump that we call a blackhead.