
Myriad causes, really. Dry shaving, shaving too fast or pushing into the skin, shaving with a dull razor, or shaving against the direction of your hair growth can contribute to it. If they pop up a few days after shaving, they’re ingrowns and you’re likely shaving too far down the hair shaft. Waxing/plucking can help reduce the amount, but growing it out and just trimming it would be a lot kinder to the skin.