What causes blackheads?

I believe that you need to know the cause of something to find a solution.

I'm not sure exactly what causes my blackheads.

I'm curious about the cause—whether it's because my face isn't being cleansed properly or if it's due to sebum secretion.

Once blackheads appear, they aren't easy to get rid of either.

I think we could prevent it if we knew the cause beforehand.