Acne occurs when oil and dead skin cells clog the pores. Pimples under the skin’s surface that erupt with a white center are called whiteheads. Pimples exposed to air are called blackheads and look black.3

Other skin blemishes may form, including:4

• Cysts
• Nodules
• Pink bumps
• Red, pus-filled pimples

Acne usually appears on the face, back, neck, chest, and shoulders.

Bacteria called Cutibacterium acnes, hormone changes, and inflammation can play a role when pimples crop up

. Some hormones trigger excess oil production, resulting in clogged pores. Adolescents are more prone to acne than others.4