Key Facts
Of note, we recognize people of all genders can be born with female reproductive organs. In this guide, we use the term “female” or “girl” to describe people who are born with uteruses/female reproductive organs.
- Puberty is when your body goes through changes and you begin to look more like an adult.
- Most girls get their period about 2-2 ½ years after they begin to develop breasts.
- Talk to your primary care provider if your body hasn’t begun to go through these changes by the time you are 13 years old.
Puberty is the name for the time when your body goes through changes and you begin to grow from a child to an adult. Your hormone levels will change; you will develop breasts, grow taller, and start your menstrual periods. Puberty in girls usually starts between 8 and 13 years of age, however, it can also be normal for girls to start puberty before 8 or after 13. If you are late or early, check with your health care provider (HCP). During puberty, similar changes happen to all girls, but the timing can different for everyone. These changes are all part of becoming an adult. For most people, they are something to welcome and celebrate, but for others, it may be more difficult. It is OK to have different feelings! When the time is right, the pituitary gland in your brain sends a signal (FSH, LH) to your ovaries for puberty to begin.
Breast development is often the first sign that puberty has begun. Your breasts will start to grow. They will start as breast “buds,” small mounds beneath the nipple, and areola. (The areola is the dark area surrounding your nipple.) One breast may start growing before the other, sometimes even 6 months before the other. In the beginning, they may hurt and sometimes be tender when they are touched. This will go away as your breasts become rounder and fuller. The nipple and areola also darken. Many girls have breasts that develop unevenly; one breast may be bigger than the other. This is perfectly normal. Many people with breasts have one that is slightly larger than the other, but the difference in breast size usually decreases as your breasts develop. Young women may have different breast sizes because of differences in families, hormones, and weight. Rapid development of breasts can lead to stretch marks sometimes, but these will lighten with time. Towards the end of puberty, you may also grow a small amount of hair around your areola.
You may need to start thinking about wearing a bra to support your breasts. Talk to your mother, an older sister, or another adult that you feel comfortable with about buying some bras.
Diagrams below show the 5 stages of breast development:
Pubic and underarm hair: You will start to grow hair around your pubic area (above vulva) and under your arms. This usually happens after you start to develop breasts, but for some people, pubic hair starts first. You will probably get pubic hair before you get underarm hair. Underarm hair usually comes near the end of puberty. At first, you will likely just have a few fine hairs in your pubic area and under your arms. Late in puberty, the hair will become thicker and curlier. Some people decide to remove the hair under their arms. There are no health reasons to do so, but some people simply prefer not to have underarm hair. It’s up to you if you want to shave. Talk to your parent or another adult that you feel comfortable talking to about this.
Diagrams below show the 5 stages of pubic hair development:
Growth spurt and body shape change: Most girls have a growth spurt the year before they get their menstrual period. Your feet and hands will usually be the first parts to grow, and then the rest of your body will follow. After you get your first period, you will grow more slowly but usually will grow about another 1 or 2 inches after your first period. During puberty, your hips will get wider as your waist gets smaller. You may develop a healthy, curvy shape. Talk to your health care provider if you are not growing and changing by age 13. It’s important to get check-ups during puberty to make sure that you are healthy.
Vaginal discharge: Most girls notice a yellow or white stain in their underpants as they go through puberty. This is a normal fluid that helps clean and moisten your vagina. However, if you have itching, odor, or irritation around your vagina, this could mean that you have an infection. If you have any of these symptoms, talk to your health care provider. You will usually get your period a year after you first have discharge from your vagina.
Skin: Your skin may get oilier. You may get some pimples and acne. This is because of more hormones and oil glands that become more active during puberty. Wash your skin at least once daily with soap and warm water and use an oil-free moisturizer. Don’t scrub too hard because this can irritate your skin and cause even more acne. Wash your hair regularly and keep your face and hands clean. You can treat acne with medications that you can buy in a pharmacy, or get from your health care provider or a dermatologist (a doctor that treats skin problems) if the problem is more serious. Birth control pills that you take by mouth often make acne better.
Sweat/Perspiration: Your sweat glands will become more active during puberty. This can cause perspiration odor. This is a good time to go shopping for deodorant, which helps control the odor.
Menstruation: You will also start getting your period. Most girls start getting their periods about 2 – 2 1/2 years after they first start developing breasts, some girls may start just 1 year after breast development, and other girls may start 3-4 years after breast development. Most girls have their first period between the ages of 12 and 13, but some girls start as early as age 9, and others as late as 15. If you are 15 and haven’t begun your period or it’s been 3 or more years since you started your breast development, check in with your health care provider to make sure you are on track.
Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.