The flood of hormones released by your body during puberty can make you sweat -- a lot. Puberty also makes the oil glands in your skin more active. Together, these two things can trigger pimples and zits. Your doctor calls this acne.
Keeping your face and body clean can help. But if your acne is very bad, ask your mom or dad to make a doctor's appointment for you. Sometimes, medicine can help clear up severe acne and avoid scarring.