
Pimples form when dead skin cells mix with excess oil (sebum). This mixture plugs the pore, causing swelling. Bacteria can grow in the mix and lead to infection and pus.
| By | Healthwise Staff |
| Primary Medical Reviewer | Kathleen Romito, MD - Family Medicine |
| Specialist Medical Reviewer | Alexander H. Murray, MD, FRCPC - Dermatology |
| Last Revised | February 3, 2011 |