Girls and Puberty

Many girls notice at an early age how their bodies are different from that of their mothers and other adult women. Eventually, girls learn what to expect with puberty, as they transition from a girl to a woman. The school curriculum, media influences, and talking with friends teaches girls how their bodies and emotions will change. It’s important for your daughter to separate fact from fiction. Before your daughter reaches the start of puberty, have an honest conversation about the changes she’s about to experience with her body. If you’re more comfortable with an expert opinion, make an appointment for the two of you to talk with your family doctor and discuss changes that occur over several years.

Definition of puberty: The period or age at which a person is first capable of sexual reproduction.

Path to improved well being

The changes associated with puberty can be difficult. Many girls anxiously await the opportunity to wear a bra for the first time or think about becoming a mom in the future. All other changes, such as your daughter’s first period (menstrual cycle) or changes to her size (wider hips) 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 the following changes occur:

  • Changes to her body (shape, breasts, period): A young girl beginning puberty will undergo several 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 will 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, and 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 and transition to tampons when they are ready.

Talk with your daughter’s doctor to determine when she can use tampons (a menstrual hygiene product inserted into the vagina). Tell her to change her tampon every 4 hours. Research shows that leaving a tampon inside the vagina for an excessive amount of time can increase the risk of Toxic Shock Syndrome (TSS), a serious staph (Staphylococcus aureus) infection caused by bacteria that can enter the bloodstream. In the case of tampon use, researchers believe that inserting a tampon can scratch the vagina and make it vulnerable to an infection. They also think tampons made with artificial fibers are more likely to trap bacteria than tampons made with 100 percent cotton.

  • Changes to her emotions: 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. Fortunately, emotions start to level out by the end of puberty. They may flair up around the time of your daughter’s period. Often called PMS (pre-menstrual syndrome), hormonal changes occurring each month around your daughter’s period 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 consequences, such as serious medical or emotional problems. However, there are instances when it’s important to call your doctor. Those times include when your daughter’s periods seem irregular beyond the first year, if she experiences more than moderate pain and cramping, if she has signs of a yeast infection or sexually transmitted disease (itching and odor near her vagina), or if she has more than light acne that won’t go away. If your daughter is experiencing serious emotional symptoms, such as depression or thoughts of suicide, see your doctor.

Questions to ask your doctor

  • My daughter started her period much earlier than age 12. Should I be concerned?
  • 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?


Girls Health

CDC, Girls and Puberty, Middle Childhood

CDC, Girls and Puberty, Young Teens