For most people, acne is an inherited condition of the pores. When someone is prone to acne, their pores clog with dead skin cells much faster than normal. Healthy pores shed about one layer of dead skin cells per day inside the pore, but acne-prone pores shed up to five layers of dead skin cells per day.

The body just can’t keep up with keeping the pore clear. Technically, this is called “retention hyperkeratosis” — dead skin cells shedding more quickly than the pore can expel them.