Back acne develops like other types of zits. Your skin’s pores (tiny holes) get clogged with dirt, dead skin cells, sweat and an oil called sebum. Your body makes sebum to keep your skin and hair from getting too dry.

If your body makes too much sebum or you don’t clean your skin properly, you can get clogged pores. Backpacks, sweaty shirts or sports equipment can create friction on your back and worsen back acne.