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Puberty is the time when kids grow into young adults through physical and emotional changes. This doesn’t happen all at once, but slowly over time. It's good to know about the changes that come along with puberty so you know what to expect.

When Does Puberty Start?

Most females will start puberty when they’re 8 to 13 years old, and most males will start between 9 and 14. But it can also be normal to start earlier or later.

How Does Puberty Start?

Hormones from the brain trigger the start of puberty. Hormones are chemical messengers that tell the body what to do.

In males: The hormones tell the testicles to make the hormone testosterone and sperm.

In females: The hormones tell the ovaries to make the hormone estrogen and triggers the growth and release of eggs.

Other puberty hormones come from the adrenal glands, a pair of glands that sit at the top of the kidneys. These hormones lead to the growth of pubic and underarm hair, body odor, and acne.

What Physical Changes Happen During Puberty?

The physical changes that happen during puberty are different for males and females.


For a male, the physical changes of puberty usually start with the testicles getting bigger. Dark, coarse, curly hair will sprout just above the penis and on the scrotum. The penis and testes will get larger, and erections happen more often. Ejaculation — the release of sperm-containing semen —also happens. Ejaculation during sleep is called a “wet dream” or nocturnal emission.

Later, hair will grow under the arms and in the beard area. And that first crack in the voice is a sign that the voice is changing and will get deeper. Some males get some breast growth (called gynecomastia). It usually goes away in 6 to 18 months.

Their body shape begins to change as their shoulders broaden and they gain weight and muscle. A growth spurt usually happens between ages 12 and 15. By age 16, most males have stopped growing, but their muscles will continue to develop.


For most females, the first physical change of puberty is breast development. It starts with small, firm, tender lumps (called buds) under one or both nipples. The breasts will get larger over the next year or two. Dark, coarse, curly hair will appear on the labia (the folds of skin surrounding the vagina). Later, more hair will grow in the pubic area and under the arms.

Their body shape begins to change as their hips widen and they gain weight and body fat. Expect the first period (menstruation) about 2 years after breast buds appear, usually between the ages of 9 and 16. Most females have a growth spurt about 1–2 years before their period starts. After they get their period, most females grow about 1–2 more inches before growth stops.

What Emotional Changes Happen During Puberty?

Just as those hormones change the way your body looks on the outside, they also change how you feel on the inside. While your body is adjusting to all the new hormones, so is your mind. During puberty, you might feel confused or have strong emotions that you've never had before. You may feel anxious about how your changing body looks. You might feel get upset or lose your temper more than usual.

It's easy to feel embarrassed or anxious when talking about these topics, but you need the right information. If you aren’t comfortable talking to your parents, you might talk to your doctor, a school nurse, a teacher, or a school counselor.

What Else Should I Know?

Even though everyone goes through puberty, we all go through it a little differently. Some of your friends might have gotten curves, but you haven't yet. Maybe your best friend's voice has changed, and you think you still sound like a kid. But eventually everyone catches up, and the differences will even out.

Keep in mind that there is no right or wrong way to look. We are all unique, on the inside and the outside.

Medically reviewed by: Amy W. Anzilotti, MD
Date reviewed: January 2023