Girls and Puberty

Last Updated May 2023 | This article was created by editorial staff and reviewed by Beth Oller, MD

Puberty is the period or age at which a person is first capable of sexual reproduction. For girls, it’s a period of change. Understanding what is happening to her body can make your daughter’s transition from a girl to a woman a positive one.

School curriculum, media influences, and talking with friends all impact how girls understand their bodies and changing emotions. It’s important to be able to separate fact from fiction. It’s important to have an honest conversation about the changes happening with her body. Or you can make an appointment for the two of you to talk with your family doctor.

Path to improved health

Some changes in puberty can be difficult. Many girls anxiously await the opportunity to wear a bra for the first time. But other changes, such as your daughter’s first period or changes to her size can be scary. Break it down for your daughter by explaining the stages of puberty that will affect her physically and emotionally.

Girls begin puberty at different ages. It can start as early as age 9. By age 15, most girls have fully developed. It’s during these years that both her body and her emotions will change.

Physical changes

In the first stage, breast development begins with the appearance of small, breast buds under the nipples. It could be 2 additional years before her breasts fully develop. Hair growth will begin on her arms, legs, armpits, and pubic area. They will begin to sweat more and produce body odor during physical activity, and pimples may begin to appear. Girls will also experience an increase in height and weight to prepare for their periods. Your daughter may notice that her arms, thighs, hips, and upper back have become fuller and wider. Eventually, her first menstrual period will start.

Most girls have their first menstrual period at age 12 or 13. Some girls experience it earlier and others get it much later. Girls may grow 10 inches and add 25 pounds to their bodies before they have their first period.

Tell your daughter what to expect during her period. In addition to vaginal bleeding, she may experience:

  • Nausea
  • Stomach cramps
  • Bloating
  • Diarrhea
  • Back pain
  • Breast pain
  • Fatigue

A period can last between 2 and 7 days. On average, a period occurs every 28 days. However, it is different for everyone. The first year of your daughter’s periods may be irregular, occurring inconsistently every month or every other month. Girls often start by using menstrual pads for their first year or period underwear, which they can use in place of pads or tampons.

When your daughter is ready to use tampons, tell her to change her tampon every 4 hours. Research shows that leaving a tampon inside the vagina for too long can increase the risk of Toxic Shock Syndrome (TSS). This is a serious infection caused by bacteria that can enter the bloodstream. Tampons made with artificial fibers are more likely to trap bacteria than tampons made with 100 percent cotton.

Emotional changes

Emotion isn’t new to girls. However, many young girls will experience a wider range of emotions when they begin puberty. Sometimes it will feel like a storm of emotions, ranging from irritability to sadness. Your daughter may experience confidence issues for the first time in her life. Emotions start to level out by the end of puberty. They may flair up around the time of your daughter’s period. This is often called PMS (premenstrual syndrome). These hormonal changes can bring about anxiety, irritability, sleeplessness, and sadness.

Things to consider

Girls generally reach their full height by the time they finish puberty. Most girls make it through puberty with no serious medical or emotional problems.

You should call your family doctor if your daughter experiences any of the following:

  • Irregular periods beyond the first year
  • More than moderate pain and cramping
  • Signs of a yeast infection or sexually transmitted disease (itching and odor near her vagina)
  • Heavy acne that won’t go away

You should also see your doctor if your daughter is experiencing serious emotional symptoms, such as depression or thoughts of suicide.

Questions to ask your doctor

  • My daughter started her period much earlier than age 12. Should I be concerned?
  • At what age should I be concerned that my daughter hasn’t started her period yet?
  • Can my daughter become pregnant between the time she starts puberty and her first period?
  • What medicine can my daughter take for the pain and discomfort of her period?
  • What is the difference between a moody teenager and PMS?
@media print { @page { padding-left: 15px !important; padding-right: 15px !important; } #pf-body #pf-header-img { max-width: 250px!important; margin: 0px auto!important; text-align: center!important; align-items: center!important; align-self: center!important; display: flex!important; }