Between the ages of 8 and 18, most people will go through a stage of development called puberty. During this time, you may experience a number of physical and emotional changes, though exactly what these are and when they happen will vary from person to person. Puberty is when a person’s body starts to change physically and mentally from that of a child to an adult. In many ways, it is an incredible part of being human and growing up. Changes in our bodies at puberty are preparing our bodies to be able to reproduce (create babies). Our bodies normally start to get ready many years before we actually want to have children. There is no ‘normal’ when it comes to puberty, and everyone experiences it differently. Some people might start experiencing signs of puberty at a young age, some might start a bit later and some will feel like it stops and starts with gaps in between. Puberty also affects people differently depending on their sex. What is sex? Sex is the word we use to talk about different types of bodies and the different role those bodies play in reproduction (having babies). We call these different bodies female and male. Although our sex may be determined by things we cannot see like our chromosomes (that sit inside the cells in our bodies), we normally decide whether someone is female or male by the bits of their body that we can see. So when a baby is born with a vulva and a vagina they will be called female/a girl. A baby born with a penis and testicles will be called male/a boy. Find out more about vulvas and vaginas.Find out more about penises and testicles. Some people are intersex which means their external body parts don’t look simply male or female when they are born. Other intersex people may not experience puberty in the way that they would expect because the things we can’t see like their reproductive organs inside their body or their chromosomes don’t match with their external body parts or genitalia (penis, vulva, etc.) You can find out more about being intersex here. People will have a different experience of puberty depending on whether they are male or female or intersex, and this is because their bodies produce different levels of hormones. It is important to remember that not everyone’s biological sex will be the same as their gender. Some people identify with a gender that is different to their biological sex, which is known as being transgender.Find out more about gender.Find out about the difference between sex and gender. The role of hormones A word that you might hear a lot in relation to puberty is ‘hormones’. Hormones are the cause of a lot of the changes that people experience during puberty. What are hormones?Hormones are chemicals that are produced naturally within the body and released into the bloodstream to send messages to other parts of the body. Different hormones will send different messages, which in turn will trigger different changes during puberty. As part of puberty, sex hormones are released and begin to cause physical changes. Sex hormones are chemicals in our bodies which produce ‘male’ and ‘female’ characteristics during puberty. The ‘male’ hormone, testosterone, is produced in the testes, which means it is usually boys/people with penises and testicles who produce more testosterone. The ‘female’ hormone, oestrogen, is produced in the ovaries, which means it is usually girls/people with vaginas and vulvas who produce more oestrogen. Most people have at least a little bit of both hormones because there are various other places in the body that these hormones are produced in smaller amounts. Changes that happen to everyone Changes to your body will happen over time and the speed of change will be different for each person. It’s normal for people to start seeing the signs of puberty at different times, so try not to compare yourself to other people . Most people will experience the following changes: You will grow taller You will grow body hair in places where you didn’t have it before, such as on your legs, armpits, genitals and face The sweat glands under your arms and between your legs will become more active You may get spots on your face and body Your hair may get more greasy Your voice will get deeper Your nipples might become more sensitive Your muscles will develop, and you might notice differences in your arms, legs, tummy and chest. Keeping cleanBecause of the hormonal changes in your body you may sweat more and your hair and skin become more greasy. It is really important to stay clean and wash regularly. You don’t need loads of fancy things on your bathroom shelf, just soap and water. Some people choose to use deodorant to stop their armpits getting smelly as the day goes on. Puberty and mental healthPuberty is a time of great transition between 'childhood and adulthood' and people often talk about the physical changes that happen as a result of that. But it's important to acknowledge the significant impact that puberty has on people's mental health.Teenagers are often described as 'moody' but this can be dismissive of the huge emotional change that puberty brings about.Remember that you and your mental health matter! Adolescence (the stage of development between being a child and being an adult) is a great time to start getting into some helpful habits and routines that can support your mental and emotional wellbeing.Find out more about mental health and emotional wellbeing here. There are also changes that might happen to different people depending on what their sex is. Boys/people with a penis If you have a penis and testicles, then it is likely that your body will produce more of the hormone testosterone than oestrogen. Here are some of the changes you can expect to happen between the ages of 10 and 18. Genitals There are various changes that will happen to your genitals as you go through puberty. Your penis and testicles will grow larger and begin to produce semen. Find out more about semen here. You will probably start to experience erections, which are when the spongy tissue of the penis fills with blood and becomes hard. This can happen when you are sexually excited, and also when you aren’t; it might seem like sometimes your penis has a mind of its own! You can find out more about erections here. You might also have wet dreams, which is when you ejaculate while you are asleep. What is ejaculation?For people with a penis, ejaculation is when semen (usually containing sperm) is discharged from the penis as the result of an orgasm. Find out more about orgasms and ejaculation here. Breast tissue growth Everyone has breast tissue, no matter their sex or gender. For boys/people with a penis, their chests will develop by growing more muscle, specifically the pectoral muscles, or ‘pecs’. It is common for levels of testosterone to drop at various points during puberty, which can result in oestrogen levels making breast tissue grow. Chests can feel tender as the breast tissue grows, and tissue may grow unevenly. Hair growth It is common for hair to grow on the armpits, chest, legs, face and around the genitals. The placement and amount of hair will vary from person to person. Girls/people with a vagina If you have a vulva and vagina, it is likely that your body will produce more of the hormone oestrogen than testosterone. Here are some of the changes you can expect to happen between the ages of 8 and 18. Genitals There are various changes that will happen to your genitals as you go through puberty. Discharge In puberty it is normal for your vagina to produce discharge – this is a small amount of clear or milky fluid that comes from the vagina and keeps it healthy. The amount of discharge can vary from day to day. If your discharge changes colour or consistency, if it smells bad, if there’s an unusual amount of it, or if you get itching around your vagina or a stomach pain, this may be the result of an infection, and you should talk to your doctor as soon as you can. Find out more about discharge here. Periods You will also start your period (menstruation) at some point during puberty. Menstruation is a part of your fertility cycle when unneeded blood and tissue is released from the womb/uterus and out of the body through the vagina. Other words for periodsThere are various different words for periods that people use, such as 'monthlies', 'that time of the month' and even some funny ones like 'a visit from Aunt Flo'! Most people who get periods have one every four to five weeks, and they generally last between a few days to a week. For some people they are regular, and for others they are irregular. It is quite common for people’s periods to be irregular when they first start having them, and for them to become more regular as they get older. It is important to know that some people’s periods don’t start until they are 16 or 17. Also, some people with vaginas don’t have periods at all. Find out more about periods here. Breast tissue growth Everyone has breast tissue, no matter their sex or gender. For girls/people with vaginas, their nipples and breasts will start to swell and fill out. It is common for one breast to develop faster than the other, and for one breast to be bigger than the other. Breasts can keep developing until 18 or beyond, and can continue to change size, shape and sensitivity throughout a person’s life, such as at different points in their menstrual cycle. Hair growth It is common for hair to grow on the armpits, legs and around the genitals. Lots of people also notice hairs appearing around the nipples, under the belly button, and on the face (such as on the upper lip and chin). The placement and amount of hair will vary from person to person. Everyone is differentAs you go through puberty, you can expect a lot of changes to happen in just a few years. This can be an overwhelming experience, especially if you feel like your body is changing in ways that are different to your friends. It can be tempting to compare yourself to other people, but there is no ‘normal’ when it comes to bodies, because everyone is different and unique. If you want to talk to someone about the changes that are happening in your body because of puberty, you can talk to your friends, family and/or a trusted adult such as a GP, a Brook service or another healthcare professional.