Puberty is the time in life when a boy or girl becomes sexually mature. It is a physical change that usually happens between ages 10 and 14 for girls and ages 12 and 16 for boys. Puberty affects boys and girls differently.
In girls:
- The first sign of puberty is usually breast development.
- Other signs are the growth of hair in the pubic area and armpits, and acne.
- Menstruation (or a period) usually happens last.
In boys:
- Puberty usually begins with the testicles and penis getting bigger.
- Then hair grows in the pubic area and armpits.
- Muscles grow, the voice deepens, and acne and facial hair develop as puberty continues.
Both boys and girls also usually have a growth spurt (a rapid increase in height) that lasts for about 2 or 3 years. This brings them closer to their adult height, which they reach after puberty.
NIH: National Institute of Child Health and Human Development
