These pesky clusters of dead skin cells and oil can be irritating and painful to remove.

Dr. Julia Carroll of Compass Dermatology in Toronto, says blackheads are formed when dead skin cells and sebum collect in openings of pores.

“When this combination of material is exposed to the air, it oxidizes, turning a black colour. Dermatologists call them open comedones. It’s important to know the cause of the dark colour, as many people think it’s dirt but it’s not,” she tells Global News.