As an adult, you probably remember puberty — a time when your body went through a lot of changes. And now you’re the parent of a child who’s experiencing these changes. You’ll want to know what to expect so you can help your child through each stage of development.
Professor James M. Tanner, a child development expert, was the first to identify the visible stages of puberty. Today, these stages are known as the Tanner stages or, more appropriately, sexual maturity ratings. They serve as a general guide to physical development, although each person has a different puberty timetable.
Read on to learn about the Tanner stages and what you can expect to see in boys and girls during each stage.
Tanner stage 1 describes a child’s appearance before any physical signs of puberty appear. Toward the end of stage 1, the brain is just starting to send signals to the body to prepare for changes.
The hypothalamus begins to release gonadotropin-releasing hormone (GnRH). GnRH travels to the pituitary gland, which is the small area under the brain that makes hormones that control other glands in the body.
These early signals typically start after a girl’s 8th birthday and after a boy’s 9th or 10th birthday. There aren’t any noticeable physical changes for boys or girls at this stage.
Stage 2 marks the beginning of physical development. Hormones begin to send signals throughout the body.
It’s common for breasts to be different sizes and grow at different rates. So, it’s normal if one bud appears larger than the other. The darker area around the nipple (areola) will also expand.
On average, Black girls start puberty a year before white girls, and are ahead when it comes to breast development and having their first periods. Also, girls with higher body mass index experience an earlier onset of puberty.
Physical changes are becoming more obvious.
Physical changes in girls usually start after age 12. These changes include:
- Breast “buds” continue to grow and expand.
- Pubic hair gets thicker and curlier.
- Hair starts forming under the armpits.
- The first signs of acne may appear on the face and back.
- The highest growth rate for height begins (around 3.2 inches per year).
- Hips and thighs start to build up fat.
Physical changes in boys usually start around age 13. These changes include:
- Penis gets longer as testicles continue to grow bigger.
- Some breast tissue may start to form under the nipples (this happens to some teenage boys during development and usually goes away within a couple of years).
- Boys begin to have wet dreams (ejaculation at night).
- As the voice begins to change, it may “crack,” going from high to lower pitches.
- Muscles get larger.
- Height growth increases to 2 to 3.2 inches per year.
Puberty is in full swing during stage 4. Both boys and girls are noticing many changes.
In girls, stage 4 usually starts around age 13. Changes include:
- Breasts take on a fuller shape, passing the bud stage.
- Many girls get their first period, typically between ages of 12 and 14, but it can happen earlier.
- Height growth will slow down to about 2 to 3 inches per year.
- Pubic hair gets thicker.
In boys, stage 4 usually starts around age 14. Changes include:
- Testicles, penis, and scrotum continue to get bigger, and the scrotum will get darker in color.
- Armpit hair starts to grow.
- Deeper voice becomes permanent.
- Acne may start to appear.
This final phase marks the end of your child’s physical maturation.
In girls, stage 5 usually happens around age 15. Changes include:
- Breasts reach approximate adult size and shape, though breasts can continue to change through age 18.
- Periods become regular after six months to two years.
- Girls reach adult height one to two years after their first period.
- Pubic hair fills out to reach the inner thighs.
- Reproductive organs and genitals are fully developed.
- Hips, thighs, and buttocks fill out in shape.
In boys, stage 5 usually starts around age 15. Changes include:
- Penis, testicles, and scrotum will have reached adult size.
- Pubic hair has filled in and spread to the inner thighs.
- Facial hair will start coming in and some boys will need to begin shaving.
- Growth in height will slow down, but muscles may still be growing.
- By age 18 most boys have reached full growth.
|Tanner stages in girls||Age at the start||Noticeable changes|
|Stage 1||After the 8th birthday||None|
|Stage 2||From age 9–11||Breast “buds” start to form; pubic hair starts to form|
|Stage 3||After age 12||Acne first appears; armpit hair forms; height increases at its fastest rate|
|Stage 4||Around age 13||First period arrives|
|Stage 5||Around age 15||Reproductive organs and genitals are fully developed|
|Tanner stages in boys||Age at the start||Noticeable changes|
|Stage 1||After the 9th or 10th birthday||None|
|Stage 2||Around age 11||Pubic hair starts to form|
|Stage 3||Around age 13||Voice begins to change or “crack”; muscles get larger|
|Stage 4||Around age 14||Acne may appear; armpit hair forms|
|Stage 5||Around age 15||Facial hair comes in|
Some people have worse acne than others. If you have a family history of acne, there’s a higher possibility your child will also experience acne.
Generally, you can treat acne by washing the affected areas regularly with a mild soap. And there are also over-the-counter (OTC) creams and ointments to help control breakouts. You may want to try some home remedies as well.
Larger sweat glands also develop during puberty. To prevent body odor, talk to your child about deodorant options and make sure they shower regularly, especially after intense physical activity. Learn more about hygiene habits for kids and teens.
It’s important to react with patience and understanding. Your child may be feeling insecure about their changing body, including their acne.
Talk about these changes and reassure your child it’s a normal part of maturing. If something is particularly troubling, talk to your child’s doctor as well.