As you transition from child to teen to adult, puberty will trigger the movement of new chemicals in your body. Depending upon whether you're a guy or girl, these hormones will go to work on different parts of the body, and of course, impact your skin.
Sebaceous (oil) gland activity is stimulated by androgen hormones. These hormones act like a switch and increase oil production and hair growth, and are responsible for the triggers that lead to oily skin and breakouts. These so-called "male" hormones are present in both males and females.
Your pores (follicles) may become enlarged, your skin texture changes and may not feel as smooth, your skin looks and feels shiny, your cheeks may feel more sensitive and look pink, and your once flawless skin may now have evident pimples, blackheads and whiteheads.
Your scalp and hair may also be oilier, and you start to grow hair in new Places. We haven't even touched on your mood swings, ability to sleep all day and body changes, such as a deeper voice for males and a lovely new body odor!
This all sounds very frightening, but the good news is that these androgens that tend to be present in relatively large amounts during adolescence become stabilised as you reach adulthood. Meaning the oily skin and breakouts will lessen and clear for most people.