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puberty; changes; sexual; development; teenager; period; menstruation; tampon; testes; testicle; adolescent development; physical changes; blushing; flushing; blush; flush; breast. ;

Puberty starts when hormones from part of the brain (pituitary gland) act on the ovaries or testes to begin sexual changes in both boys and girls.


Puberty is the time of change when young people begin to develop the outward signs of becoming an adult and when they become able to reproduce (have a baby). Puberty starts when hormones from part of the brain (pituitary gland) act on the ovaries or testes to begin sexual changes in both boys and girls.

Changes for both girls and boys

  • The skin often becomes oily, often resulting in pimples (acne). (See the topic 'Acne' for more information)
  • Hair often becomes oily and may require more frequent washing. After a while, the body will become used to the hormonal changes and the oiliness of the hair will settle down.
  • The sweat glands become more active resulting in increased perspiration and requiring young people to shower more frequently and possibly to use a deodorant.
  • Changes will occur in the voice of both boys and girls, but more especially in boys. The voice will become lower and more adult in sound. Boys will find their voices will crack and squeak when they are speaking and this may last for a few months and up to a whole year, while the vocal chords become fully developed.
  • A growth spurt occurs which takes place over 2-3 years. Girls may grow up to 11 cms in a year, and boys up to 13 cms in a year. Teenagers will still grow a further 1 to 2 cms after the main growth spurt.

Puberty in girls

  • Usually begins between 9-14 years. It can begin as early as 8 or later, up to 16 years and still be quite normal.
  • It takes approximately 2 years from the start of puberty until a girl has her first period.

First stage (first 2 years)

  • The visible physical changes start with changes to the breasts (budding).
  • Her hips will widen and pubic hair will begin to grow.
  • Both breasts do not necessarily grow at the same rate. The difference in size is not permanent. However, if there is a marked difference, seek advice from a doctor.
  • Under arm hair develops next and the hair on legs and arms will become darker.
  • Girls do most of their growth spurts in both height and weight in the first 2 years of puberty.
  • They may start to have regular mood swings and even abdominal pain up to a year before periods start.

Second stage (next 2 years)
When a girl first starts menstruating:

  • her periods may be irregular
  • the period loss may be very slight or quite heavy
  • a period may last from three to seven days, with a heavier loss at the start of the period
  • many girls get pain on the first day of periods (often after they have started ovulating - producing eggs)
  • usually, girls do not ovulate for the first few months to a year or so after their periods start. There may be a whitish discharge at the time of ovulation
  • once girls start to ovulate, they are fertile (able to have a baby)
  • some girls suffer from mood changes and other symptoms of pre menstrual tension for up to a week before their period
  • too much exercise or weight loss can cause periods to stop or become irregular after they have started
  • her body will develop more into the shape of a woman over the next 2 years. Her hips will become rounded and more shapely
  • once periods have begun, girls continue to grow in both height and weight but more slowly
  • girls grow an average of 5 - 11 cm a year in height and add an average of 3 - 5.5 kgs per year of weight for 3-4 years.
  • There is more about periods in the topic Periods - the facts.

How parents can support girls

  • Help girls to see that this is an important and exciting milestone in growing up.
  • Girls should be prepared for their first period, what to expect, what periods are like and what they mean, how to be prepared, by carrying a pad in a purse etc.
  • Younger girls may need help in understanding how to use a pad or tampon and what to do with used ones.
  • Explain the need for hygiene eg to change pads/tampons regularly including not using tampons overnight.
  • Make sure that her school has a place that she can be private, somewhere she can dispose of pads, someone to turn to if she is having too much pain etc.
  • Reassure the girl that it is usual for a girl's breasts to be slightly different in size but that the difference is not noticeable to others.
  • Talk about the possibility of periods being irregular both in how much blood she loses and how often they happen.
  • If she has a lot of pain with her period, a hot water bottle, some exercise or a warm bath may help and pain relief medicines such as paracetamol or ibuprofen (see your pharmacist). If the pain is distressing, other medicines can help. Talk to a doctor.
  • If her period does not start when her friends are starting, reassure her that it will happen. Some girls like to wear a bra before they need one to feel part of the group. A soft bra, like a sports bra, can be good to start with.
  • Consult a doctor if she has not had a period by the time she is 16 or 17, or if periods stop after they have started.
  • There are several topics on the Teen Health section of this site that she may find interesting:
    Puberty - what it feels like  
    Puberty - what it looks like 
    Periods - the facts   
    Periods - what to do   

Puberty in boys

  • Boys usually start to change and develop about 2 years after girls, from about 11 to 13 years - but the changes can happen earlier.
  • Usually, the first visible signs are developing pubic hair and growth of the genital organs (penis and testes). These are followed by growth of under arm hair, then hair on the face, upper lip, legs and abdomen.
  • Hair does not start to grow on the chin until the genital organs are fully developed.
  • Boys experience involuntary ejaculations during sleep (wet dreams), often with erotic dreams from early puberty, and need to be reassured that this is normal.
  • They also need to know that masturbation is normal and does not cause health problems if they do not know this already.
  • Boys grow an average of 7 - 13 cm a year in height and an average of 4.5 -9 kgs per year for weight for approximately 4 years.
  • Many boys develop some breast tissue during the changes of puberty.  It starts like the development of breasts in girls, but it stops while there is only a small amount of breast tissue.  This is normal and the breasts flatten again by the end of puberty. Have a look at the topic  Male breasts (Gynecomastia).
  • They may be interested in reading the topic Men's stuff on the Teen Health section of this website.

How parents can support boys

  • Reassure their son that testes are often not exactly the same size. In a lot of men, the left testis is lower than the right.
  • If the testes are very small, or not both in the scrotum, consult a doctor.
  • Reassure the boy, if he is concerned because he is very thin and tall, that he will probably gain weight as he gets older.
  • If a boy is worried about the size of his penis, reassure him that sexual functioning does not depend on penile size, and that erect penises are usually very similar in size.

Emotional changes 

  • Unexplained changes of mood are part of the hormonal changes of puberty. Sometimes they seem to start almost overnight. There may be very sudden explosions of anger or slumps into misery and also swings from feeling independent and free to wanting the parental support they had in childhood.
  • Young people are needing to establish their own identity as separate from parents. This often means not doing what parents want for a while until they feel secure enough to agree without feeling they have lost their identity.
  • Young people are having to learn very quickly to adjust to an entirely new body shape and they become very interested in, and often very sensitive about, how they look.
  • They may be very embarrassed about their bodies and try to hide them by wearing loose clothing and they often have an intense need for privacy when they are not fully dressed.
  • There is a need for privacy and personal space in other ways as well. Young people more often share their secrets and innermost thoughts with friends than with parents. They are intensely private about their bedrooms.
  • The topic Young people, feelings and depression has links to other sites for more information if you are worried about your teenager.


  • When someone is anxious or upset, their body makes adrenalin (epinephrin) so that they can fight or run away (depending on what is needed).
  • Nowadays fighting or running away is not usually either possible or useful, but the adrenalin is still made.
  • One effect of adrenalin is to make the heart beat faster, and another is to dilate (expand) the blood vessels which causes a flush (or blush).
  • Both of these mean that there is more oxygen and energy going to muscles ready for fighting (or running away).
  • Almost everyone flushes and has a faster heart rate in some situations eg when standing up in front of a group or when they are angry, but most people around them do not notice.
  • On some people, especially those with pale skin, the flush is easier to see, but most people would think that the person is being brave for standing there and talking even though she or he is flushed.
  • Because this flushing and fast heart rate is a natural reaction of the body, stopping it means interfering with the normal reactions of the body, and is not recommended.
  • Practising talking in front of groups (or whatever the situation is that causes blushing) can help a person feel more confident, even though sometimes the flush still comes. This is the best way of managing.

When puberty happens early or late

  • Puberty is said to be early if it starts before eight years in girls, or before nine in boys. It’s considered late if there are no signs of puberty by 13 years in girls, and 14 in boys.
  • To find our more have a look at the topic When puberty is early or late on the Raising Children Network website 

What parents can do

  • Compliment their young people about their looks and what they do well. Even if they brush compliments off - they still hear them.
  • Support young people in taking care of their bodies and feeling good about them even if it seems excessive, eg hours in the bathroom, or very different hair cuts. Try to negotiate some limits, eg how long is reasonable for a shower.
  • If young people want to change their bodies in permanent ways eg tattoos, talk with them about the pros and cons of this, and ask them to think about alternatives such as tattoo stamps or henna tattoos (henna is painted on and stays for several days). If they are sure they want to do it, you and they can get more intormation from topics on the Better Health Channel - Piercings and Tattoos   
  • Avoid mentioning things like pimples directly (it can seem like criticism). If parents know a brilliant 'cure' it is best to wait until the young person says something or leave information about, or talk about it indirectly.
  • Accept that young people will make lots of mistakes as they try their wings and try not to say "I told you so". Help them see that we all make mistakes and mistakes are to learn from.
  • Think about what the young people's behaviour means. It is usually not just to "get at" parents, but because they are struggling with becoming individuals and all the other pressures of adolescence. The meaning parents make of it affects how they respond.
  • Try to keep calm when young people suddenly become angry or attacking. Letting it develop into a major argument does not help. It is best to accept that they are feeling that way at the time and when they have cooled down talk about whatever the problem is.
  • Parents are not necessarily to blame even if it seems they are being blamed. It is often easier to take out hurt and angry feelings at home where the young person feels safe. However it is important to try to 'get into their shoes' to see if parents can do something differently that will help.
  • Do not push to find out everything the young person is thinking and feeling. Keep the opportunities for sharing open by spending time together without pressure and being interested in their interests. If they do share feelings try to listen without criticism or taking over. Be available.
  • Talk things over with your partner or other parents of teenagers. It helps to get it into perspective.
  • Encourage them by your attitude and what you say to see puberty as an exciting new development in their lives.
  • Parents have rights and responsibilies towards their teenagers. Have a look at this topic What about parent's rights?.
  • If things get really bad between you, you could look at the topic Violence towards parents by young people.

Separated or single parent families

  • Girls and boys often feel more comfortable talking about personal issues with someone of their own sex. If this cannot be a parent there may be another adult who relates well to young people who could do this. This happens even with very caring parents and is part of growing up.
  • Developing adolescents need their privacy respected whatever the family structure.
  • If girls are living with their father for part of the time there needs to be a place at his house where pads or tampons are kept in case a period starts during this time. Her mother (or another woman) could arrange this with the father before periods start and then let the girl know what she can do and that her privacy will be respected.
  • Girls also need to be told how to dispose of used pads or tampons at their father's house, eg put them in plastic bags and take them to the rubbish bin, or have a special lidded bin for the girl in the bathroom.

Parents' feelings

  • Adolescence brings big changes for parents as well as for young people. The beginning of puberty signals the changes that will take your child from your care and control to being an independent adult.
  • Parents need to be able to 'let go' many things that have been a big part of your lives.
  • It is important for parents to spend time thinking of your own needs, new directions etc.
  • Parents also need to be aware that they may have feelings of disappointment and loss if a young person chooses a different direction from the one you felt would be best, and to accept that you have done your part and may not be able to change the young person's directions.
  • Parents do have a right to say how you feel and what you believe in a caring way, but accept that your young person has the final choice. Parents need to make sure they have thought through what they believe so they can back up what they say with reasons.
  • Remember young people still do need their families, no matter how it may seem, and caring parents are the best support they can have.
  • You may be interested in reading the topic What about parent's rights.

More information

There are many topics on the Teen Health and Kid's Health sites which address issues about puberty.

There is also a lot of information about these issues on the Raising Children Network site in the section Pre-teen physical development

Reachout has a lot of information for young people experiencing tough times. https://au.reachout.com/

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The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).

This topic may use 'he' and 'she' in turn - please change to suit your child's sex.

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