Blackheads form when sebaceous glands produce excess oil and dead skin cells are not shed properly, creating a plug in the pore opening. Hormones, genetics, certain cosmetics, smoking, diet, and skin damage (including UV) can all contribute to this process.
On their own, blackheads are not dangerous and mainly cause cosmetic and psychological discomfort. However, many comedones can signal hormonal or metabolic issues and may progress to inflamed acne if bacteria overgrow inside the clogged pores.
Single, small blackheads that don’t bother you often need no treatment and may clear on their own. For multiple or persistent comedones, treatment usually includes gentle cleansing, chemical exfoliants (like salicylic acid), retinoids, and sometimes professional extraction or peels under a dermatologist’s or cosmetologist’s supervision.