The fuller answer
Acne forms when oil, dead skin cells, inflammation, and bacteria affect hair follicles. Puberty hormones increase oil production, so blackheads, whiteheads, inflamed bumps, and deeper nodules can appear on the face, chest, shoulders, and back.
Acne is not caused by being dirty, masturbation, or one “bad” food. Scrubbing and squeezing can worsen inflammation and scarring. Treatments need consistent use for weeks, not one or two days.
Early care matters when acne is painful, deep, leaving dark marks or scars, or affecting school and confidence. Effective prescription treatments exist, and severe acne is not a character test.