Puberty for Girls


Body Changes and Development in Females


Puberty is the changes in our bodies created by hormones. The changes include growth, sexual characteristics, the maturation of reproductive organs that results in the ability to have children. It also includes changes in metabolism, personality, and mood.


Before we can learn about puberty, we need to make sure we know the correct terminology for female reproductive organs and genitals.

Female reproductive organs include internal and external parts. In a person who is born biologically female, the external organ is known as the vulva. The vulva includes the pubic mound, inner and outer labia, the clitoris, and the external opening of the urethra and vagina.

The internal reproductive organs include the vagina, ovaries, fallopian tubes, and a uterus. Each body has two ovaries on one the right and one on the left. The ovaries contain a lifetime supply of eggs. When menstruation begins, an egg will be released each month. The egg will be captured by the fallopian tubes and transported to the uterus. The uterus is a muscular organ that can expand to nurture and grow a baby. The uterus connects to the vagina via the cervix. The cervix will open and dilate during the birth of a baby (and to a lesser degree each month when menstrual blood is expelled. The vagina connects the cervix with the outside of the body. The vagina measures 3.5 inches and can stretch or shrink.


The trigger that starts puberty is not understood. We know that once this trigger happens the pituitary gland (a gland in the brain) signals to the ovaries to start making estrogen. Estrogen will cause the reproductive organs and secondary sex characteristics, such as hip and breast development, to occur. The trigger happens between 7-11 years of age for most girls with noticeable changes happening between 8-13 years of age. Puberty can take 5-7 years total from trigger until full growth and maturation.


Breast Development

Breast development is usually the first sign of puberty in girls. Breast development is the result of estrogen causes fat build in in the connective tissue of the breasts. Breast development starts with breast buds. Breast buds are small dime or nickel-sized bumps of tissue under the nipple. Sometimes breast buds can occur in one breast before the other breast. They can also be sore or tender.

After breast bud growth, the glandular tissues of the breast will increase in size. The duct system in the breasts also begins to grow. The breasts may start out “pointy” appearing, but the bottom of breasts will start to take on a “cupped” appearance before menstruation begins. After menstruation begins, the breast and milk duct system continue to grow and mature. Glands will form at the end of the milk ducts. During this sage the areola and nipple become more raised, and the top half of the breast will develop a cupped appearance.
During a menstrual cycle, hormones stimulate the milk ducts to grow. This can cause swelling, pain, and soreness in the breast. It can also change breast texture causing the breast to feel “lumpy”. Once you get a period, the breasts return to normal size and texture.

Breast development may result in your child needing to wear a bra for coverage and support. There are many cute and comfortable styles to choose from and companies that cater towards young girls and teens. Most girls start with training bras which are lightweight bras that are made for children who do not fit in standard bra sizes yet. Sports bras can also make great first bras. If your child is involved in sports, they can be worn for comfort and support during practices and games. As your child’s breast sizes increased, they may move into bras sized by band and cup size. Measuring your child before purchasing type of bra can help ensure a proper fit. A correct fitting bra will have a band that is level around the body. The straps should not be falling off her shoulders nor digging into her shoulders.

Hair Growth

Pubic hair growth is the first sign of puberty in 15% of girls meaning it will occur before noticeable breast budding. Most girls though, pubic hair starts growing when the glandular tissue of the breast starts to increase in size.

Pubic hair starts out sparse but over 1-2 years increases in density, develops into a triangle shaped distribution, and becomes coarser and curlier. Pubic hair may also be noted on upper and inner thighs.

Girls also develop underarm (axillary) hair as well as thicker hair on their legs. The appearance of hair can bother some girls. Hair removal is a personal choice. There is no medical reason you must remove hair from your body. Hair removal may include shaving, waxing, laser removal, sugaring, or threading. If your child will be shaving, make sure you demonstrate the correct method and discuss changing out razors, infection prevention, ingrown hair prevention, as well as how to take care of cuts.

It is also currently “trendy” to remove all pubic hair, do not be surprised if your child shaves or removes this hair. It is particularly important to be careful around the genitals. This hair is thicker and more prone to ingrown hairs so care in prepping the skin should be taken.


Vaginal discharge can start 6-12 months before menarche, or the start of menstruation. This is a response to rising estrogen in the body. Discharge should be clear or white and thin. Green or thick white discharge should be discussed with your provider.


Menstruation occurs when an egg, or ovum, is released by the ovaries. This causes hormones to signal to the body to create endometrium, or a cushy, nourishing lining, in preparation for a baby. If the egg is not fertilized, the body will then clean out the uterus and expel the lining through the vagina. The expelling of the lining is called menstruation or a period. The body will expel about 2 tablespoons of blood. Due to other bodily fluids, the amount may be higher.

This process is repeated monthly. Menarche is when you start having periods. This means your body has reached the point where reproduction is possible.

The biggest, most anxiety provoking, event of puberty is menarche. Menarche is NOT a random event that happens during puberty. It happens at a set time in the process and is one of the later parts of puberty. Most girls will start get their period, 2-3 years after breast bud development. Girls may get their period between ages 10-15 with the average age in the United States being 12 years. Before a girl starts their period, they usually grow to be within 1-2 inches of their adult height. They also need to have a minimum of 17% body fat.

A girl’s first period may be heavy or light. Her period may be red or brown. Periods last between 1 to 7 days. Periods occur monthly but the normal cycle for a teen can be 21-45 days. As they approach adulthood cycles should be between 21-35 days. Periods can be very irregular for the first few years. This is normal (but annoying). Using a period tracking app can be helpful for a teen to learn more about their cycle length and period duration.

It is important for girls to know that periods are normal. Every person born a female will experience a period. A person does not need to change their activity levels because of their period. They can attend school, exercise, and do all social activities. They can swim with the use of the correct period products. These will be discussed further on.

Period Symptoms

Some people experience cramping when they have their period. Cramping is caused by contractions of the uterus that help to expel the lining. Cramping usually is worse the first day or two of a period, then improves. You may even notice cramping a day before your period starts. Cramping can be treated with exercise, a warm compress, a warm bath, and pain medication. If cramping is severe, causing vomiting, or causing your child to miss school or activities, please discuss this with their primary care provider. Headaches are also a common period symptom. Rest, fluids, and pain medication can be helpful.

Premenstrual syndrome is the physical and emotional symptoms that a person has 1-2 weeks before their period. These can include acne, bloating, fatigue, back pain, breast tenderness, constipation, diarrhea, food cravings, moodiness, and trouble sleeping. Like many other things, a person many have no symptoms, or a combination of symptoms and the severity of these symptoms may be different for each person. It may also be different every cycle for a person. These symptoms will improve after a person’s period starts.

Period Management

Before your child has their first period, they should have access to a kit in their school, sports, or travel bag as well as have supplies at home. A kit should include extra underwear, wipes, and pads. They can also include tampons and quarters for extra supplies.

It is important to discuss with your child different ways to manage their period. This includes discussing different products as well as hygiene.


Pads are flat absorbent material placed in underwear that absorb menstrual fluids. They come in a variety of sizes and absorbencies. They should be used once and changed every 3-4 hours. Pads should be thrown out after being wrapped up in toilet paper and disposed of in the trash, they should never be flushed. You can purchase or make reusable menstrual pads. These should be worn for 4-6 hours then cleaned appropriately.

Panty liners are thin pads that can be used for heavier vaginal discharge, very light menstrual flow, or for back up with other period products.


Tampons are cylinder-shaped pieces of cotton that are inserted into the vagina. Tampons absorb menstrual fluids while in the vagina. They come in different sizes and absorbencies. They should be changed every 3-6 hours and only used once. Most tampons have applicators that are removed after inserting though there are brands that do not have applicators and are inserted using a finger. A tampon is removed by pulling on the attached string.

The first time using a tampon can be scary. Your vagina is a muscle and will clench if you are nervous. Pick a time when you are not rushed or stressed in trying to use the tampon. A slim or light-flow tampon, which are usually smaller, and a plastic applicator can be helpful when you are learning how to insert a tampon. You can also put KY Jelly on the tip of the tampon to help it insert more easily. Exploring how the applicator and tampon works before trying to insert it into your body can be helpful to see how it functions. If you insert the tampon and it is painful, that usually means it is not fully inserted. Remove it and try again. Do not leave it in as it will result in chafing, swelling, and pain. A correctly inserted tampon should not be painful.

Menstraul Cups and Discs

Menstrual cups are silicone, rubber, or latex cups that are inserted into the vagina. They sit against the cervix to collect menstrual fluids. Cups come in a few sizes and can be made of softer or more rigid material. They now make teen sizes made for smaller bodies. They need to be removed and cleaned every 12 hours. They can be reused many times but once they are showing signs of cracking or significant wear, should be replaced.

Menstrual cups are inserted into the vagina without an applicator. A person will need to be comfortable with their own body and the proper insertion methods. There are many YouTube videos that demonstrate different “folds” and insertion methods (these are not graphic) that are useful before using these cups. To remove a menstrual cup, a person will bear down and tug gently on the loop or “stem” of the cup. The contents of the cup are then emptied into the toilet.

A newer product is menstrual disc which is like a flattened version of a cup but has a more flexible center material. It is also held in the vagina by sitting on the pelvic bone (the cup is held in by suction). It is like a cup in that it needs to be emptied and cleaned every 12 hours. It is reusable. It also requires similar insertion to a cup. Removal requires hooking a finger around the disk and then pulling the disc out to be emptied.

Period Underwear and Swimsuits

Period underwear and swimsuits are clothing that that contain built in liners of absorbent material in the crotch area to catch menstrual fluids. These items can hold a few tampons worth of menstrual fluids. They can be used exclusively during a period or used as back up to tampons or menstrual cups or discs to prevent leaking during your period. Period underwear should be changed every 6-12 hours. They should be hand-washed and air-dried. They can be used repeatedly and will stay absorbent for up to 2 years.


When a girl goes through puberty, they experience 25% of all their lifetime growth! Most girls will grow upwards of 10 inches and 30-50 pounds in 3-4 years. This growth is very important, and it is important to prepare girls and NORMALIZE this much growth. Their body needs to increase fat stores. The fat stores help create hormones and increase bone density. The increase in body fat stores cause hips to widen and breasts to develop.

The most significant amount of height growth will occur in the 6-12 months before their period, and it may result in over 3 inches of growth. After this growth spurt, their height will only increase another 1 to 2 inches. It is uncommon to grow more than these 1 to 2 inches.

Growth does not happen equally in all body parts. First hands and feet grow, then arms and legs grow longer. After limb growth, hips widen, and trunk and face bones grow larger or longer. When the face and neck bones grow longer, voices will become lower in pitch.


Acne is a common occurrence during puberty. This is due to hormones and increased oil production. Even with the best skin care, adolescents can still get acne. Acne may occur on face, back, and chest. A good skin care routine with over-the-counter acne products can be helpful. If this does not improve acne, please consult your primary care provider as prescription medications are available.

Frustratingly, both over-the-counter products and prescription products can take 6-8 weeks to make a noticeable difference, and most teens are not known for their patience. Encourage your teen to give a new medication or routine time to work.

Body Odor

Body odor is actually a very early sign of body changes and can occur years before starting puberty! Body odor is the result in puberty changes in sweat glands. Puberty causes sweat glands to change and produce more sweat. The body also produces new chemicals and hormones as well as increases the production of skin oils. The combination of sweat, hormones, oil, and the bacteria found on skin creates strong body odor. Odor can be noted underarms, and from feet and genitalia.

When body odor occurs, it is important to discuss hygiene with your child. Some people cannot smell their own odor, or they may be embarrassed and not know what to do with their body odor. Discuss that they may need to shower, with soap, daily. Increase oil production can also affect hair requiring more frequent shampooing. Deodorant or antiperspirants can help reduce sweating and odor. Your child may also need to launder their clothing and bedding more frequently.


Puberty is an emotional rollercoaster! Even before physical changes occur you may notice mood swings. Emotions may change without reason. Emotions may rapidly change. A person may feel overly sensitive, angry, or sad. They may feel uncertain.

Puberty is also a time where a person may be looking for their identity and who they are outside of their family. It is a normal time for kids to want more privacy from parents and siblings.

Puberty itself can trigger a lot of different emotions. They may be sad to be leaving childhood behind. They may be upset that their body is changing. They may feel self-conscious about puberty, their body changes, and their looks and personality.

During puberty, children also develop new sexual feelings. They also are interested in romantic relationships.
This is NORMAL. Is it easy to live with? Absolutely not! But knowing it is normal, that you probably did the same exact thing, can allow us to give our children some grace. If emotions are extreme or your child is feeling sad or depressed for long periods of time, please discuss this with your primary care provider.

Puberty for Transgender Children

Puberty can result in high levels of anxiety for transgender children. This is a time where their body is changing in ways that further the discrepancy between their gender identity and the sex they are assigned at birth. It is important to discuss puberty with your primary care provider. Transgender children should see an endocrinologist to discuss puberty blockers. Puberty blockers are medications that block the physical changes of puberty. These effects are temporary, once the medication is stopped, puberty will resume. Puberty blockers allow transgender children to delay puberty. This gives them time to make decisions that are best for them in an unhurried way.

Medical Care

Before puberty starts and during puberty, body changes may be discussed at yearly well exams. Yearly exams will help ensure puberty is starting when it should but also will be a time for your child to learn and ask about puberty and body changes in a comfortable setting. The needs for good nutrition, daily exercise, and rest should also be discussed.

A child or adolescent does not need to see a gynecologist until age 21 unless there is an issue that requires a special level of care. Currently pelvic exams and Pap smears are not done until age 21. Breast exams are not currently recommended in pediatric patients. Adolescents are low risk for breast cancer. It is normal for a teen to have breast changes that cause swelling and tenderness. This is normal. If a lump does not go away with a period cycle or pain or redness is present, please have your child evaluated.

Early or Late Puberty

What is early or late puberty? When should you be worried?

Early Puberty

Early puberty is when puberty starts before the age of 8. This is more likely to happen in Black or Hispanic girls as well as obese children or children who were born very small for their gestational age. We are unsure why this happens earlier in some children.

There are a few causes of early puberty. Sometimes the body is just speeding up the normal process. Sometimes it is because of abnormal pituitary gland activity. This is called CPP or central precocious puberty. If this is the cause of puberty, an endocrinology will evaluate your child and treat this with medications that turn off the signal to start puberty. This allows puberty to be delayed to a more normal age and allows a child to reach a taller adult height.

Premature Adrenarche is when a child has body odor and pubic or underarm hair before 8 years of age BUT has no breast development. This is caused by the adrenal glands (glands on top of the kidneys) secreting hormones that cause these changes. This is not true puberty and does not require treatment. Children who have premature adrenarche tend to be taller. They are also at increased risk of polycystic ovarian syndrome (PCOS) when they are older.

Late Puberty

Late puberty is when puberty has not start in girls by age 13 of if the girls has undergone pubertal changes but no period by age 16. Constitutional delayed puberty, or late bloomers, is inherited from a parent. A parent would have also had delayed puberty with the mother not having her first period by age 14 or a father not growing until after age 16. There is no treatment needed.

Delayed puberty can also happen due to a person not having enough body fat. This is seen in patients who are athletes doing sports that require thin body types such as gymnastics, ballet, or competitive swimming. It can also be the result of eating disorders or chronic illnesses.

Problems with ovaries, either not developing properly, or being damaged can also delay puberty. Such causes include primary ovarian insufficiency, Turner syndrome, radiation or certain cancer treatments, immune system damage, and pituitary insufficiency.

If your daughter has not started puberty by age 13, they should be evaluated by their primary care and potentially an endocrinologist. Treatment would be based on the cause and may include gaining weight or hormone replacement.


BOOKS: link here



Amaze is a website with quick 2–5-minute video providing medically accurate, age-appropriate, affirming honest puberty (and sexuality) education. The videos are short and engaging!


Puberty brings a lot of changes. These changes can be scary, but knowledge is power! The more your child knows about the changes that may occur, the less afraid they will be of those changes. Having open conversations about these changes and resources available for reference, will help your child through this transition. Next week we will learn about puberty in boys!

Children’s Health Care of Newburyport, Massachusetts and Haverhill, Massachusetts is a pediatric healthcare practice providing care for families across the North Shore, Merrimack Valley, southern New Hampshire, and the Seacoast regions. The Children’s Health Care team includes pediatricians and pediatric nurse practitioners who provide comprehensive pediatric health care for children, including newborns, toddlers, school aged children, adolescents, and young adults. Our child-centered and family-focused approach covers preventative and urgent care, immunizations, and specialist referrals. Our services include an on-site pediatric nutritionist, special needs care coordinator, and social workers. We also have walk-in appointments available at all of our locations for acute sick visits. Please visit where you will find information about our pediatric doctors, nurse practitioners, as well as our hours and services.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

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