What Is Puberty? The Complete Beginner's Guide

Puberty is the stretch of time when your body gradually changes from a child's body into an adult's body. It happens to everyone, it follows a fairly predictable pattern, and it is a completely normal part of growing up. Knowing what to expect can make the whole process feel a lot less confusing.

Key takeaways

• Puberty is the natural process that turns a child's body into an adult's body, driven by hormones.
• It usually starts between ages 8 and 13 for girls and between 9 and 14 for boys.
• Changes happen slowly over about 2 to 5 years, not all at once.
• Everyone has their own timetable, so comparing yourself to friends is not a useful measure.
• Puberty affects feelings and thinking too, not only your body.

What puberty actually is

Puberty is a phase of development in which the body matures physically. Bones lengthen, muscles and body shape change, hair grows in new places and the reproductive system becomes mature. By the end of puberty, your body has reached its adult height and form.

The word "adolescence" is often used alongside puberty. Puberty refers to the physical changes. Adolescence is the wider period, roughly from about age 10 into the early twenties, that also includes emotional, social and mental growth.

Why puberty happens

Puberty is controlled by hormones, which are chemical messengers that travel through your blood and tell different parts of your body what to do.

Here is the basic chain of events:

1. A part of the brain called the hypothalamus starts releasing a hormone called GnRH in a regular pattern.
2. This signals the pituitary gland, a small gland at the base of the brain, to release two more hormones: LH and FSH.
3. These hormones travel to the ovaries or testicles, which then make more of the sex hormones estrogen or testosterone.
4. Those sex hormones cause most of the visible changes of puberty.

The adrenal glands, which sit on top of the kidneys, also make hormones that contribute to body odor, oily skin and some hair growth. That is why these changes sometimes show up a little before other signs.

When puberty starts

There is a wide window of normal. The table below shows typical starting ages.

Girls tend to start about one to two years earlier than boys. This is why, around ages 11 to 13, many girls are temporarily taller than boys the same age. Boys usually catch up and often pass them later.

Your genes play the biggest role in timing. If a parent started early or late, there is a good chance you will too. Overall health, nutrition and body weight also have some influence.

The main changes to expect

Puberty brings many changes. Some happen to everyone, and some are more specific to girls or boys.

Changes that happen to everyone

• Growth spurt: a period of rapid growth in height, often several centimeters per year.
• Body hair: hair starts to grow under the arms and in the pubic area, and hair on the arms and legs often gets darker.
• Skin changes: skin and hair become oilier, and acne is very common.
• Sweat and body odor: sweat glands become more active, so daily washing and deodorant become more important.
• Emotional changes: stronger feelings, mood swings and a growing desire for independence are typical.

Changes more typical for girls

• Breasts develop gradually over several years.
• Hips widen and body shape becomes curvier.
• Periods (menstruation) begin, usually about 2 to 3 years after breasts start developing.
• A clear or whitish fluid called vaginal discharge may appear before the first period. This is normal.

Changes more typical for boys

• The testicles and penis grow.
• The voice deepens, sometimes with a few months of cracking.
• Shoulders broaden and muscle mass increases.
• Facial hair begins to grow, usually later in puberty.
• Some boys notice temporary swelling under the nipples. This is common and usually goes away on its own.

Puberty and your feelings

Your brain is changing during puberty too. The parts that handle emotions develop earlier than the parts responsible for planning and self-control, which can make feelings seem bigger and harder to manage.

You might notice:

• Feeling self-conscious about how your body looks
• Moods that shift quickly
• Wanting more privacy and independence
• Caring more about what friends think

All of this is normal. Getting enough sleep (teens need about 8 to 10 hours), staying active and talking with people you trust can really help.

How to take care of yourself

A few simple habits make puberty easier:

• Shower or bathe daily, especially after exercise.
• Use deodorant or antiperspirant once sweat and odor increase.
• Wash your face gently twice a day to help manage acne.
• Eat a balanced diet with enough calcium, iron and protein to support growth.
• Move your body most days, in whatever way you enjoy.
• Ask questions. Parents, caregivers, school nurses and doctors have all answered these questions many times before.

When to talk to a doctor

Most of the time, puberty unfolds on its own without any problems. It is a good idea to check in with a doctor if:

• A girl shows signs of puberty before age 8, or a boy before age 9.
• A girl has no breast development by age 13, or a boy has no testicular growth by age 14.
• A girl has not had her first period by age 15, or within 3 years of breasts starting to develop.
• Puberty starts and then seems to stop or go backward.
• You have worries about your growth, weight, skin or mood that are affecting your daily life.

An early or late start is often just a family pattern, but a doctor can check whether anything needs attention.

The bottom line

Puberty is a gradual, natural process that every person goes through, and there is no single "right" time for it to happen. Your body knows what it is doing. Look after yourself, be patient with the changes, and remember that asking questions is a smart and healthy thing to do.