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    Everything you need to know about the stages of puberty

    Updated 11 April 2023 |
    Published 01 April 2019
    Fact Checked
    Medically reviewed by Dr. Oluyemisi Adeyemi-Fowode, Obstetrician and gynecologist, pediatric and adolescent gynecology specialist, Texas Pediatric & Adolescent Gynecology, Texas, US
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    From your boobs developing, to hair growing in places you never thought it would, and starting your period — puberty is a lot! Here, we break it down into easy stages so you can understand what might happen during puberty and when. 

    Let’s face it: It’s normal to feel a bit weird about puberty. It’s all too easy to compare yourself to your peers and feel like your body is changing too much, too quickly, or too slowly. Knowing what to expect (and when) may make you feel more comfortable and confident as your body develops.

    While puberty can look different for everyone, it generally starts between the ages of 8 and 13, with 10 being the average age to start puberty. It lasts, on average, around 5 years, although this can be different for everyone. During this time, you might pick up on physical changes as well as developments in your mood and emotions. To help you navigate this and answer all of your burning questions, two Flo experts give you the lowdown on puberty

    What is puberty? 

    You’ll likely have heard the term puberty used in your health class. This is the name given to the natural process of your body changing from a child to an adult. When you hear the word puberty, you might think of your period starting or your body changing, but these processes actually all start in the brain in a region called the hypothalamus. 

    The hypothalamus is the area of the brain that starts to release hormones that instruct other parts of your body to start growing and changing. These hormones are called follicle-stimulating hormones and luteinizing hormones. They act as a green light for your ovaries, triggering the production of estrogen and progesterone. Among other things, these hormones regulate your cycle (establishing when you release an egg, which is known as ovulation, and when you’ll have your first period). You can learn all about your cycle using an app like Flo.  

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    When does puberty start and end? 

    As we now know, puberty can be slightly different for everyone, but for most girls and people assigned female at birth, this time of change begins between the ages of 8 and 13 years old. Remember the hormones we mentioned earlier? Well, between the ages of 9 and 10, you experience a surge in hormones in preparation for all the physical changes your body needs to make over the following few years. This is around two years earlier in girls than in boys.

    These physical changes you experience during puberty can hit at different times. However, generally, you’ll notice these milestones:

    • Your breasts will start to develop (this is called breast budding)
    • Your pubic hair will grow
    • You’ll experience a growth spurt
    • You’ll have your first period 

    You can learn more about the different stages of puberty below. Since puberty can be a little bit unpredictable, it’s impossible to know exactly when puberty will start and end. While most people finish puberty by 18, that’s not the case for everyone. It’s totally normal for your body to continue changing after that, and you might notice that some of your premenstrual syndrome (PMS) symptoms mimic what you’ve experienced during puberty. 

    5 Tanner stages of puberty 

    You might notice which of your friends is wearing a bra or shaving their legs to establish who hit puberty first, but there’s also a scientific way to classify some of the physical changes you experience during puberty. It’s called the Tanner stages or the sexual maturity rating. Named after Professor James M. Tanner, a child development expert, the Tanner stages refer to the ways in which breasts, pubic hair, and male genitalia change during puberty. Your body changes in a number of ways during your teen years; they’re not limited to your boobs and body hair. However, you might be able to relate to some of the Tanner stages. 

    Tanner stages in females

    While the five Tanner stages might give you an idea of what to expect, it isn’t a strict timeline, and you might experience these signs of puberty in a different order. It also isn’t an exhaustive list of all the ways your body will change during puberty. 

    Stage 1
    • You currently don’t have any pubic hair.
    • You don’t have any visible breast growth or development.
    Stage 2
    • You start to develop soft, downy pubic hair. 
    • You might start to notice breast buds forming under your nipple. They might appear like raised bumps. 
    Stage 3
    • The pubic hair starts to grow. It might start to appear a little bit thicker and grow in patches.
    • Your breast buds will continue to grow and may appear fuller or rounder.
    Stage 4
    • The pubic hair continues to grow and covers the vulva. 
    • Your breasts may appear fuller now, looking more like boobs rather than buds. The area around your nipple, called your areola, will also get bigger.
    Stage 5
    • The pubic hair covers your vulva and beyond. (You might notice hair in the crease of your inner thighs or down the insides of your legs.)
    • Your breasts will continue to grow and change shape. Most people notice that their boobs change throughout their adult life — this isn’t something that stops at puberty. 

    Changes to your body during puberty 

    The physical changes listed above aren’t the only developments you’ll notice during your teen years. Knowing what you could expect can help you feel in control. So let’s dig into those first physical signs of puberty.  

    Breast development

    It might feel like your boobs appeared overnight, but as we now know, this process starts quite gradually, with breast buds being the first sign that you’ve started puberty. Your breasts will take a few years to fully develop, and it’s important to remember that they come in all shapes and sizes. One may be larger than the other, your boobs might feel sore and tender as they grow, or they may be slightly different shapes, and that’s OK: all bodies are beautiful! Finding a supportive bra may ease any growing pains. 

    Body hair

    As the Tanner stages suggest, your pubic hair will grow and may change in texture as you move through your teen years. Puberty also causes hair growth in your armpits as well as on your legs and arms. Everyone has it, so don’t feel ashamed. Whether you want to keep or remove it is completely up to you — there’s no medical or hygienic benefit to getting rid of it. 

    Changing body shape and height

    During puberty, you’ll have a growth spurt and get taller, your hips will get wider, and your breasts will start to develop, meaning you might look a little curvier. You might feel like you’re coming out of puberty in an entirely different body than you started, but try to embrace it if you can, as this is totally normal. 


    Waiting for your period to start can feel daunting, especially if your friends have already had their first one. Generally, you’ll have your first period a couple of years after you’ve started puberty, which is why it happens at different times for everyone. Your period is when the lining of your uterus breaks down and flows out of your vagina, and it’s nothing to be scared of. It might feel like you’re losing a lot of blood, but on average, you only lose between 1 and 5 tablespoons of blood per period. You can learn all about your period and predict when it will happen using an app like Flo

    Other physical changes

    Your first period might feel like the biggest milestone of puberty, but it’s among a number of other physical changes that aren’t touched upon in the Tanner stages. 

    Vaginal discharge

    Discharge is a white or clear fluid that you might notice on your underwear, and while it might be confusing to see at first, it’s perfectly normal. Discharge, which is also known as cervical mucus, starts to appear during puberty and is there to keep your vagina healthy. Most women and people who menstruate have some discharge every day, but if it starts to bother you in any way or your vagina becomes sore or itchy, or you notice a change in the color or smell of your discharge, then it’s definitely worth talking to your doctor about.

    Spots and acne

    Acne is triggered by puberty hormones as your skin becomes more oily and your pores can become clogged, so it’s common to get pimples on your face (or other parts of your body, like your back). That doesn’t mean it doesn’t suck, though! You might find yourself feeling a little self-conscious about acne, but remember that it’s very common throughout your teenage years, and chat with your doctor if you’re worried. The good news? There are lots of treatments that can help.


    It’s inconvenient, but it’s a fact of life: Puberty causes you to sweat more. You can reduce your chances of having body odor by wearing deodorant, washing more, and wearing loose-fitting clothing. And if you’re feeling really self-conscious about the way you smell, then speak to a trusted adult about what you might be able to do to improve things. 

    Navigating the way your body is changing can feel like uncharted waters. Your body is becoming more adult, and that’s what’s supposed to happen, but growing up can still feel strange and awkward sometimes. It’s natural to feel uncertain and self-conscious during puberty. If you have any questions, then reach out to an adult you trust; this could be a parent, teacher, sibling, or friend. And remember that while puberty can be uncomfortable, you’re growing into the adult you’ll become — and that’s pretty wonderful. 

    Internal changes

    As your body is changing on the outside, you’re also changing on the inside. Your reproductive organs — such as your uterus, uterine tubes, ovaries, and vagina, grow and elongate as you move through your teen years. You might not be totally sure what each of these parts does, and that’s totally normal. You can learn all about your vulva here. 

    Emotional changes

    Puberty doesn’t just impact the way you look — emotional changes are just as important. As your body produces hormones, you may experience ups and downs or mood swings. This is all part of puberty, but if you’re worried or feel depressed, speak to a doctor. You can also use an app like Flo to fully understand what’s happening with your hormones at this time. 

    It’s also worth remembering that puberty also brings about lots of exciting feelings: having your first crush, succeeding at school, and getting closer to friends. Your teen years are full of a lot of amazing firsts, so embrace the highs as well as the lows and remember it’s all part of growing up. 

    What affects the duration of puberty?

    While puberty is something we all go through at some point during our teens, lots of things can affect how long it lasts. “There are a huge number of variables that impact the start time and duration of puberty,” explains Dr. Katie Blundell, a pediatrician at London’s Chelsea and Westminster Hospital, United Kingdom. “These include your gender, ethnicity, genetics, nutrition, and physical activity.” 

    Studies have highlighted that if you’re Black or Hispanic, you may start puberty a little bit earlier (around seven and a half years old rather than eight). Similarly, links have been made between childhood body size and an earlier onset of puberty. 

    While all of these factors might give you a better chance at guessing when you’ll notice the telltale signs of puberty, Dr. Sara Ritchie, assistant professor of pediatrics at the University of South Carolina, United States, says there’s one key factor that might unlock some answers for you. In general, your personal genetics are the most important factor in the timing of puberty,” she says. So, if you feel comfortable, it might be best to ask a family member when they started to see a change. 

    When to see a doctor 

    Although it can feel uncomfortable and sometimes a bit embarrassing, puberty is a totally natural process. “If you think anything you’re experiencing is unusual, don’t worry about speaking to a doctor or other health professional,” says Dr. Blundell. “We’ve seen it all before and are happy to check whether anything might be abnormal.” Remember that the average age to start puberty is 10, but this can vary for different people. 

    You might be worried that you haven’t seen as many physical changes as you thought you would have, but rest assured that it’s incredibly rare not to hit puberty at all. If you haven’t noticed the first signs of your breasts developing by the age of 13 and if your period hasn’t started by the age of 15, then it may be a good idea to reach out to your doctor. This may be considered to be delayed puberty. 

    Answering the internet’s most asked questions about puberty

    If any aspect of puberty has ever left you feeling stumped and you’ve found yourself turning to the internet, then you’re not alone. The web is teaming with questions all centered around what is going on. So we thought we’d answer some of the most common queries.  

    How can I determine what stage of puberty I’m at?

    The Tanner stages of puberty may give you an indication, or you can look at trusted websites like The American College of Obstetricians and Gynecologists or NHS. 

    Does puberty end at 18?

    Most people finish puberty by the age of 18, but that’s not the case for everyone. It’s totally normal for your body to continue changing after that. 

    At what age do you fully hit puberty?

    Puberty is a years-long process, so there isn’t an exact time when you fully hit it. As we mentioned earlier, you might start puberty earlier or later than your friends, and that’s totally normal. 

    Stages of puberty: The takeaway

    Puberty is different for everyone. It might feel like you’re tackling mood changes one week and your first period in the next. While this can be a time of daunting firsts, there’s also a lot of excitement to look forward to in your teen years. You may have your first kiss, start to make big decisions about your future, and make friends you’ll have for life. 

    Puberty is a natural process that’s part of growing up, but that doesn’t mean that coping with a rapidly changing body isn’t challenging at times. Try to be compassionate toward yourself, and if you have any questions or worries, then don’t be embarrassed to speak to an adult you trust. They’ve been in your shoes. 


    “Acne.” NHS, Accessed 6 Mar. 2023.

    “Delayed Puberty.” Nemours TeensHealth, Accessed 6 Mar. 2023.

    “Early or Delayed Puberty.” NHS, Accessed 6 Mar. 2023.

    Emmanuel, Mickey, and Brooke R. Bokor. “Tanner Stages.” StatPearls, StatPearls Publishing, 2021.

    Fisher, Marisa M., and Erica A. Eugster. “What Is in Our Environment That Effects Puberty?” Reproductive Toxicology, vol. 44, Apr. 2014, pp. 7–14.

    Howard, Sasha. “Timing of Puberty: Why Is It Changing and Why Does It Matter?” Society for Endocrinology, 18 Dec. 2019,

    “Hypogonadotropic Hypogonadism.” Penn Medicine, Accessed 6 Mar. 2023.

    “Puberty for Girls: What To Expect.” Cleveland Clinic, 17 June 2022,

    “Normal Breast Development.” Stanford Medicine Children’s Health, Accessed 6 Mar. 2023.

    Peper, Jiska S., and Ronald E. Dahl. “Surging Hormones: Brain-Behavior Interactions during Puberty.” Current Directions in Psychological Science, vol. 22, no. 2, Apr. 2013, pp. 134–39.

    “Precocious Puberty.” Mayo Clinic, 15 Feb. 2021,

    “Puberty.” Banner Health, Accessed 6 Mar. 2023.

    “Puberty.” Cleveland Clinic, Accessed 6 Mar. 2023.

    “Puberty.” MedlinePlus, July 2010,

    “Vulvovaginal Health.” The American College of Obstetricians and Gynecologists, Accessed 6 Mar. 2023.

    Welt, Corrine K. “Normal Menstrual Cycle.” UpToDate, 2023.

    “Your Changing Body: Puberty in Girls.” The American College of Obstetricians and Gynecologists, Accessed 6 Mar. 2023. 

    “Your First Period.” The American College of Obstetricians and Gynecologists, Accessed 6 Mar. 2023.

    History of updates

    Current version (11 April 2023)

    Medically reviewed by Dr. Oluyemisi Adeyemi-Fowode, Obstetrician and gynecologist, pediatric and adolescent gynecology specialist, Texas Pediatric & Adolescent Gynecology, Texas, US

    Published (01 April 2019)

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