If acne is bad, pimples can be large and painful. Acne often begins in your teenage years, when your skin makes too much oil. You're more likely to have pimples on your face, chest and back. These areas contain many oil glands. The bacteria cause red, swollen pimples.
Some medicines can also cause pimples.
If you're worried about what a medicine might do to your skin, talk to your doctor. Dirty skin and foods like chocolate, pizza or soda do not cause pimples. Masturbating or thinking about sex does not cause pimples either. Wash your face twice a day with a mild soap and warm water. Don't scrub your skin or use harsh soap.