Puberty is the time in life when a boy or girl becomes sexually mature. It is a process that usually happens between ages 10 and 14 for girls and ages 12 and 16 for boys. It causes physical changes, and affects boys and girls differently.

In girls:

• The first sign of puberty is usually breast development.
• Then hair grows in the pubic area and armpits.
• 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 facial hair develops as puberty continues.

Both boys and girls may get acne. They 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.

The time in one's life when sexual maturity takes place is known as puberty. The physical changes that mark puberty typically begin in girls between ages 8 and 13 and in boys between ages 9 and 14.

Precocious puberty is a condition that occurs when sexual maturity begins earlier than normal. Precocious (meaning prematurely developed) puberty begins before age 8 for girls and before age 9 for boys.

Children affected by precocious puberty may experience problems such as:

• Failure to reach their full height because their growth halts too soon
• Psychological and social problems, such as anxiety over being "different" from their peers. However, many children do not experience major psychological or social problems, particularly when the onset of puberty is only slightly early.

Delayed puberty is the term for a condition in which the body's timing for sexual maturity is later than the normal range of ages.

Many children with delayed puberty will eventually go through an otherwise normal puberty, just at a late age. Other children have a long-lasting condition known as hypogonadism (pronounced HI-poe-GO-nad-iz-uhm) in which the sex glands (the testes in men and the ovaries in women) produce few or no hormones. For example, hypogonadism can occur in girls with Turner syndrome or in individuals with hypogonadotropic (pronounced HI-po-GO-nah-doe-TROH-pik) hypogonadism, which occurs when the hypothalamus (pronounced HI-po-THAL-uh-muss) produces little to no gonadotropin-releasing hormone (pronounced goh-nad-uh-TROH-pin) (GnRH).

Puberty is the body's natural process of sexual maturation. Puberty's trigger lies in a small part of the brain called the hypothalamus, a gland that secretes gonadotropin-releasing hormone (GnRH). GnRH stimulates the pituitary gland, a pea-sized organ connected to the bottom of the hypothalamus, to emit two hormones: luteinizing (pronounced LOO-tee-uh-nize-ing) hormone (LH) and follicle-stimulating hormone (FSH). These two hormones signal the female and male sex organs (ovaries and testes, respectively) to begin releasing the appropriate sex hormones, including estrogens and testosterone, which launch the other signs of puberty in the body.

Puberty is the stage of development at which individuals become sexually mature. Though the outcomes of puberty for boys and girls are very different, the hormonal control of the process is very similar. In addition, though the timing of these events varies between individuals, the sequence of changes that occur is predictable for male and female adolescents. As shown in image, a concerted release of hormones from the hypothalamus (GnRH), the anterior pituitary (LH and FSH), and the gonads (either testosterone or estrogen) is responsible for the maturation of the reproductive systems and the development of secondary sex characteristics, which are physical changes that serve auxiliary roles in reproduction.

The first changes begin around the age of eight or nine when the production of LH becomes detectable. The release of LH occurs primarily at night during sleep and precedes the physical changes of puberty by several years. In pre-pubertal children, the sensitivity of the negative feedback system in the hypothalamus and pituitary is very high. This means that very low concentrations of androgens or estrogens will negatively feed back onto the hypothalamus and pituitary, keeping the production of GnRH, LH, and FSH low.

As an individual approaches puberty, two changes in sensitivity occur. The first is a decrease of sensitivity in the hypothalamus and pituitary to negative feedback, meaning that it takes increasingly larger concentrations of sex steroid hormones to stop the production of LH and FSH. The second change in sensitivity is an increase in sensitivity of the gonads to the FSH and LH signals, meaning the gonads of adults are more responsive to gonadotropins than are the gonads of children. As a result of these two changes, the levels of LH and FSH slowly increase and lead to the enlargement and maturation of the gonads, which in turn leads to secretion of higher levels of sex hormones and the initiation of spermatogenesis and folliculogenesis.

In addition to age, multiple factors can affect the age of onset of puberty, including genetics, environment, and psychological stress. One of the more important influences may be nutrition; historical data demonstrate the effect of better and more consistent nutrition on the age of menarche in girls in the United States, which decreased from an average age of approximately 17 years of age in 1860 to the current age of approximately 12.75 years in 1960, as it remains today. Some studies indicate a link between puberty onset and the amount of stored fat in an individual. This effect is more pronounced in girls, but has been documented in both sexes. Body fat, corresponding with secretion of the hormone leptin by adipose cells, appears to have a strong role in determining menarche. This may reflect to some extent the high metabolic costs of gestation and lactation. In girls who are lean and highly active, such as gymnasts, there is often a delay in the onset of puberty.

Signs of Puberty

Different sex steroid hormone concentrations between the sexes also contribute to the development and function of secondary sexual characteristics. Examples of secondary sexual characteristics are listed in image.

As a girl reaches puberty, typically the first change that is visible is the development of the breast tissue. This is followed by the growth of axillary and pubic hair. A growth spurt normally starts at approximately age 9 to 11, and may last two years or more. During this time, a girl’s height can increase 3 inches a year. The next step in puberty is menarche, the start of menstruation.

In boys, the growth of the testes is typically the first physical sign of the beginning of puberty, which is followed by growth and pigmentation of the scrotum and growth of the penis. The next step is the growth of hair, including armpit, pubic, chest, and facial hair. Testosterone stimulates the growth of the larynx and thickening and lengthening of the vocal folds, which causes the voice to drop in pitch. The first fertile ejaculations typically appear at approximately 15 years of age, but this age can vary widely across individual boys. Unlike the early growth spurt observed in females, the male growth spurt occurs toward the end of puberty, at approximately age 11 to 13, and a boy’s height can increase as much as 4 inches a year. In some males, pubertal development can continue through the early 20s.

In Girls

The signs of puberty include:

• Growth of pubic and other body hair
• Growth spurt
• Breast development
• Onset of menstruation (after puberty is well advanced)
• Acne

In Boys

The signs of puberty include:

• Growth of pubic hair, other body hair, and facial hair
• Enlargement of testicles and penis
• Muscle growth
• Growth spurt
• Acne
• Deepening of the voice

To identify whether a child is entering puberty, a pediatrician (a physician specializing in the treatment of children) will carefully examine the following:

• In girls, the growth of pubic hair and breasts
• In boys, the increase in size of the testicles and penis and the growth of pubic hair

The pediatrician will compare what he or she finds against the Tanner scale, a 5-point scale that gauges the extent of puberty development in children.

Pimples. Growing breasts. Body hair. Moody moments. If any of this sounds familiar, you’re likely on the path of puberty. It’s a road everyone travels, and it certainly has its bumps. But it’s also an amazing time.

Puberty is when you start making the change from being a child to being an adult. And it’s when your body develops the ability to have a baby. It all happens thanks to changing hormones, or natural body chemicals.

With everything that’s changing, life can feel a little overwhelming. But you can feel more in control if you take good care of your body. Knowing what to expect can help, too, so keep reading. (And don’t forget that puberty also involves changes you can’t see — like changes to your self-esteem and your feelings.

Timing and stages of puberty

Adolescence and puberty can be so confusing! Here’s some info on what to expect and when:

• Puberty in girls usually starts between the ages of 8 and 13 and ends by around 14. For boys, puberty usually starts between 10 and 14, and ends by around 15 or 16.
• For girls, one of the first signs of puberty usually is their breasts starting to grow.
• Getting your period (menstruation) usually happens later, around two years after breast growth starts.
• In between, you’ll probably start to see more hair in places like under your arms and in your pubic area.
• Puberty involves big changes to your shape, including getting taller (which stops when puberty ends).

Of course, it can be hard to have your body change at a slower or faster rate than your friends’ bodies. If how fast or slow your body is changing is upsetting you, talk to an adult you trust.

If you’re developing slower or faster than you think you should, your body may just be changing at its own natural rate. It’s a good idea to let your doctor know if you start puberty before age 8. Also let your doctor know if you don’t have any signs of puberty by the time you’re 14. Your doctor can check whether a medical problem is involved.

Changes to your shape

How your body looks changes a lot during puberty. For one, usually between the ages of 9 and 13, girls grow much faster than they had been growing. This process, called a growth spurt, happens later for boys. That explains why you may be taller than the boys in your grade for a while.

You likely will also see lots of other changes in your body during puberty. Keep reading for info on:

Changes in your body during puberty

These are some of the changes you can expect during puberty:

• A curvier shape
• Wider hips, thighs, and bottom
• Normal weight gain as your body structure grows
• Stretch marks, or little scars, where your skin was pulled from growing fast (but that usually fade over time)

You’ll also see more body hair, changes to your breasts, and possibly some acne. We’ve got lots of helpful tips on each of those topics, too!

Keep in mind that these changes all are common and normal! And make sure to take good care of your great, growing body. With everything that's going on, it’s important to eat well, stay fit, and get enough sleep.

Your feelings about your changing body

During puberty your body may seem very different from what you’re used to, and you might feel uncomfortable or shy about it. Remember that everyone goes through these changes — it’s just part of life — and every girl grows at her own pace.

During puberty, it’s common to struggle with body image, or how you feel about your body. This can be especially hard when models in magazines have bodies that seem “perfect.” But a lot of what you see in magazines and online is either fake or unhealthy.

If you think you or a friend may have a problem with body image or an eating disorder, talk to a parent, a doctor, or another adult you trust. Help is available, and it’s important to get treated. You can get better!

Remember, measure yourself by your great traits and loving heart — not by the size and shape of your body!

Changes to your breasts

It’s natural for girls to wonder about their breasts: Are they too big? Too small? If your breasts are large, they may get you unwanted attention. If they’re small, you may worry that they’ll never grow. Remember that your breasts don’t need to look like your friend’s breasts or a magazine model’s breasts. The world would be boring if everyone looked the same!

What happens to breasts during puberty?

Throughout puberty, you will experience changes in your breasts. The first change is developing a very small bump under the nipple. Early on, you may also notice that your breasts feel a little itchy or achy. Later on, they also may feel tender or sore during your period.

Keep in mind that it is very common for your two breasts to be different sizes, especially as they first start to grow. Other people can’t tell that your breasts are different sizes. Give your body time to grow at its own rate and in its own way. Vitamins, herbal teas, and creams — even exercises — won’t change the size of your breasts.

What about lumps and other changes?

Most of the changes your breasts will go through are normal. Let your doctor know if you find a lump or have a pain that you are not sure about. Although lumps are common in young women, keep in mind that it is very rare for the lumps to be cancer.

Should I wear a bra?

Wearing a bra can help support and protect your breasts. If you find that exercise is not as comfortable when your breasts start to grow, try wearing a sports bra with a snug fit for support.

Are you having a hard time finding a bra that fits well? Often, you can get help in a department store or special bra store. There are certain steps people there can take for measuring your body to get a good fit.

Body hair

Even before you get your first period, you will likely see new hair growing in your pubic area, under your arms, and on your legs. The hair may start out light and there won’t be a lot of it, but then it will grow darker and thicker as you go through the stages of puberty. Hair in the pubic area starts near the opening and spreads up in a V shape over time.

Body hair is normal, and some people think it looks cool. Lots of women and girls remove body hair from places such as their legs and underarms, although there is no real health reason to do so.

If you are thinking about removing hair for the first time, it makes sense to talk to your parents or guardians. They may have an opinion about how old you should be to start removing hair or advice on ways to do it.

Keep reading for some tips on ways to remove body hair.

Ways to get rid of hair

Removing body hair can cause skin irritation, cuts, and other problems. Some parts of your body, like areas around your eyes and vagina, can be especially sensitive. Also, if you have a lot of hair on your face, it could be a sign of a medical condition called PCOS.

Here are some tips to help prevent problems when using some popular ways to remove body hair.

Shaving

• Try shaving in the shower when your skin is soft.
• Use a shaving cream or gel.
• Change razors often because a sharp blade helps prevent cuts.
• Shave in the direction the hair grows.
• To avoid spreading infections, don’t share razors.

Hair removal creams, gels, and liquids (depilatories)

• These use chemicals to make the hair melt, and the chemicals can irritate your skin.
• Follow the directions carefully, and leave the product on only for the recommended amount of time.
• Don’t use these near your eyes or on skin that is already cut or irritated.
• These sometimes can cause rashes, burns, and other skin problems, so it’s a good idea to test a product on a small area the first time you use it. You might want to avoid these products if you tend to have sensitive skin (like if skin care products give you stinging, burning, or a rash).

Waxing

• Waxing involves putting cold or hot wax on skin where you want hair to be removed. A cloth is used to pull off the wax and the hair. Waxing can hurt, and it may irritate your skin.
• You can buy waxes to use yourself, or you can go to a salon professional for waxing. If you wax yourself, make sure to follow all directions that come with the product.
• You might avoid waxing if you have sensitive skin. Also, avoid waxing skin that is sunburned, chapped, irritated, or has moles or warts on it.
• It can be a good idea to do a test on a small area for allergic reaction or irritation.

Electrolysis

• In electrolysis, a professional uses an electric current to kill the hair root.
• Electrolysis can take many sessions and a lot of money.
• You could get an infection from a dirty needle or scars from poor treatments, so consider asking your doctor to recommend a trusted electrologist. You also should look for an electrologist with a current license or certification.

Laser hair removal

• Light is beamed through the skin to stop hair growth.
• The laser light can cause pain sometimes, but creams are used to numb the skin. If you use a lot of these creams, they can cause serious health problems, so talk to your doctor before having laser hair removal.
• Avoid sunlight when your skin is healing after laser removal.
• Keep in mind that laser treatment can be expensive and works best on dark hair and light skin.

Tips for removing pubic hair

In recent years, more girls and women have also begun removing all or some of the hair around their vagina. There is no need to remove the hair to keep the area clean. The decision to remove pubic hair often is based just on trends, which change over time.

If you’re thinking about removing pubic hair, keep a few facts in mind:

• Your pubic hair helps protect the sensitive lips around the opening to your vagina from painful rubbing by your underwear.
• The pubic area is very sensitive. It can easily get irritated or infected when removing hair.
• Waxing works by pulling out the hair, which can hurt.
• If you shave, you can give yourself a painful cut.
• As shaved hair grows back, it can feel itchy and uncomfortable.
• If you decide to use a hair-removal cream, make sure it says it’s gentle enough for the pubic area.
• Don’t put on any product that could sting, like aftershave lotion. To help avoid irritation, don’t use products with added dyes or fragrances.

If you have more questions about taking care of this sensitive area, talk with an adult you trust.

Changes in your mind

During puberty, changes don’t happen only to your body — changes happen in your mind, too.

• You are able to understand more complex matters.
• You are starting to make more of your own moral choices.
• You know more about who you are, and what your likes and dislikes are.
• You may have some new, strong emotions.

The teen years can seem like an emotional roller coaster, with worries about your changing looks, the demands of school, and pressure to fit in. You might feel alone on this ride, but everyone struggles with it. And some of your experiences have to do with the physical changes of this age, including shifts in your hormones and a brain that’s developing just like your body is.

A new you

Even though this can be a stressful time, it’s also a great chance to figure out who you are, what you care about, and how to value and respect the person you’re becoming!

If you’re feeling overwhelmed by some of the changes you’re going through, talking can help. Don’t be afraid to go to a parent, school counselor, or other adult you trust. They were young once, too!

Developmental Milestones

Your child’s growing independence from the family and interest in friends might be obvious by now. Healthy friendships are very important to your child’s development, but peer pressure can become strong during this time. Children who feel good about themselves are more able to resist negative peer pressure and make better choices for themselves. This is an important time for children to gain a sense of responsibility along with their growing independence. Also, physical changes of puberty might be showing by now, especially for girls. Another big change children need to prepare for during this time is starting middle or junior high school.

Here is some information on how children develop during middle childhood:

Emotional/Social Changes

Children in this age group might:

• Start to form stronger, more complex friendships and peer relationships. It becomes more emotionally important to have friends, especially of the same sex.
• Experience more peer pressure.
• Become more aware of his or her body as puberty approaches. Body image and eating problems sometimes start around this age.

Thinking and Learning

Children in this age group might:

• Face more academic challenges at school.
• Become more independent from the family.
• Begin to see the point of view of others more clearly.
• Have an increased attention span.

Positive Parenting Tips

Following are some things you, as a parent, can do to help your child during this time:

• Spend time with your child. Talk with her about her friends, her accomplishments, and what challenges she will face.
• Be involved with your child’s school. Go to school events; meet your child’s teachers.
• Encourage your child to join school and community groups, such as a sports team, or to be a volunteer for a charity.
• Help your child develop his own sense of right and wrong. Talk with him about risky things friends might pressure him to do, like smoking or dangerous physical dares.
• Help your child develop a sense of responsibility—involve your child in household tasks like cleaning and cooking. Talk with your child about saving and spending money wisely.
• Meet the families of your child’s friends.
• Talk with your child about respecting others. Encourage her to help people in need. Talk with her about what to do when others are not kind or are disrespectful.
• Help your child set his own goals. Encourage him to think about skills and abilities he would like to have and about how to develop them.
• Make clear rules and stick to them. Talk with your child about what you expect from her (behavior) when no adults are present. If you provide reasons for rules, it will help her to know what to do in most situations.
• Use discipline to guide and protect your child, instead of punishment to make him feel badly about himself.
• When using praise, help your child think about her own accomplishments. Saying “you must be proud of yourself” rather than simply “I’m proud of you” can encourage your child to make good choices when nobody is around to praise her.
• Talk with your child about the normal physical and emotional changes of puberty.
• Encourage your child to read every day. Talk with him about his homework.
• Be affectionate and honest with your child, and do things together as a family.

Child Safety First

More independence and less adult supervision can put children at risk for injuries from falls and other accidents. Here are a few tips to help protect your child:

• Protect your child in the car. The National Highway Traffic Safety Administration recommends that you keep your child in a booster seat until he is big enough to fit in a seat belt properly. Remember: your child should still ride in the back seat until he or she is 12 years of age because it’s safer there. Motor vehicle crashes are the most common cause of death from unintentional injury among children of this age.
• Know where your child is and whether a responsible adult is present. Make plans with your child for when he will call you, where you can find him, and what time you expect him home.
• Make sure your child wears a helmet when riding a bike or a skateboard or using inline skates; riding on a motorcycle, snowmobile, or all-terrain vehicle; or playing contact sports.
• Many children get home from school before their parents get home from work. It is important to have clear rules and plans for your child when she is home alone.

Healthy Bodies

• Provide plenty of fruits and vegetables; limit foods high in solid fats, added sugars, or salt, and prepare healthier foods for family meals.
• Keep television sets out of your child’s bedroom. Limit screen time, including computers and video games, to no more than 1 to 2 hours.
• Encourage your child to participate in an hour a day of physical activities that are age appropriate and enjoyable and that offer variety! Just make sure your child is doing three types of activity: aerobic activity like running, muscle strengthening like climbing, and bone strengthening – like jumping rope – at least three days per week.
• Make sure your child gets the recommended amount of sleep each night: For school-age children 6-12 years, 9–12 hours per 24 hours (including naps)

Developmental Milestones

This is a time of many physical, mental, emotional, and social changes. Hormones change as puberty begins. Most boys grow facial and pubic hair and their voices deepen. Most girls grow pubic hair and breasts, and start their period. They might be worried about these changes and how they are looked at by others. This also will be a time when your teen might face peer pressure to use alcohol, tobacco products, and drugs, and to have sex. Other challenges can be eating disorders, depression, and family problems. At this age, teens make more of their own choices about friends, sports, studying, and school. They become more independent, with their own personality and interests, although parents are still very important.

Here is some information on how young teens develop:

Emotional/Social Changes

Children in this age group might:

• Show more concern about body image, looks, and clothes.
• Focus on themselves; going back and forth between high expectations and lack of confidence.
• Experience more moodiness.
• Show more interest in and influence by peer group.
• Express less affection toward parents; sometimes might seem rude or short-tempered.
• Feel stress from more challenging school work.
• Develop eating problems.
• Feel a lot of sadness or depression, which can lead to poor grades at school, alcohol or drug use, unsafe sex, and other problems.

Thinking and Learning

Children in this age group might:

• Have more ability for complex thought.
• Be better able to express feelings through talking.
• Develop a stronger sense of right and wrong.

Positive Parenting Tips

Following are some things you, as a parent, can do to help your child during this time:

• Be honest and direct with your teen when talking about sensitive subjects such as drugs, drinking, smoking, and sex.
• Meet and get to know your teen’s friends.
• Show an interest in your teen’s school life.
• Help your teen make healthy choices while encouraging him to make his own decisions.
• Respect your teen’s opinions and take into account her thoughts and feelings. It is important that she knows you are listening to her.
• When there is a conflict, be clear about goals and expectations (like getting good grades, keeping things clean, and showing respect), but allow your teen input on how to reach those goals (like when and how to study or clean).

Child Safety First

You play an important role in keeping your child safe―no matter how old he or she is. Here are a few tips to help protect your child:

• Make sure your teen knows about the importance of wearing seatbelts. Motor vehicle crashes are the leading cause of death among 12- to 14-year-olds.
• Encourage your teen to wear a helmet when riding a bike or a skateboard or using inline skates; riding on a motorcycle, snowmobile, or all-terrain vehicle; or playing contact sports. Injuries from sports and other activities are common.
• Talk with your teen about the dangers of drugs, drinking, smoking, and risky sexual activity. Ask him what he knows and thinks about these issues, and share your thoughts and feelings with him. Listen to what she says and answer her questions honestly and directly.
• Talk with your teen about the importance of having friends who are interested in positive activities. Encourage her to avoid peers who pressure her to make unhealthy choices.
• Know where your teen is and whether an adult is present. Make plans with him for when he will call you, where you can find him, and what time you expect him home.
• Set clear rules for your teen when she is home alone. Talk about such issues as having friends at the house, how to handle situations that can be dangerous (emergencies, fire, drugs, sex, etc.), and completing homework or household tasks.

Healthy Bodies

• Encourage your teen to be physically active. She might join a team sport or take up an individual sport. Helping with household tasks such as mowing the lawn, walking the dog, or washing the car also will keep your teen active.
• Meal time is very important for families. Eating together helps teens make better choices about the foods they eat, promotes healthy weight, and gives your family members time to talk with each other.
• Limit screen time for your child to no more than 1 to 2 hours per day of quality programming, at home, school, or afterschool care.