What is puberty?
Puberty is the time when your child moves through a series of significant, natural and healthy changes. These physical, psychological and emotional changes are a sign that your child is moving from childhood towards adulthood.
Changes in puberty include:
- physical growth and development inside and outside children’s bodies
- changes to children’s sexual organs
- brain changes
- social and emotional changes.
When does puberty start?
Puberty starts when changes in your child’s brain cause sex hormones to start being released from the gonads, which are the ovaries and testes.
This typically happens around 10-11 years for girls and around 11-12 years for boys.
But it’s normal for the start of puberty to range from 8-13 years in girls and 9-14 years in boys.
There’s no way of knowing exactly when your child will start puberty. Early changes in your child’s brain and hormone levels can’t be seen from the outside, so it’s easy to think that puberty hasn’t started.
Puberty can be completed in about 18 months, or it can take up to 5 years. This range is also completely normal.
Girls: key physical changes in puberty
In girls, these are the main external physical changes in puberty that you can expect.
Around 10-11 years
- Breasts will start developing. This is the first visible sign that puberty is starting. It’s normal for the left and right breasts to grow at different speeds. It’s also common for the breasts to be a bit tender as they develop. If your child wants a bra, a soft crop top or sports bra can be a good first choice.
- A growth spurt occurs. Some parts of the body – like the head, face and hands – might grow faster than limbs and torso. This might result in your child looking out of proportion for a while. On average, girls grow 5-20 cm. They usually stop growing at around 16-17 years.
- The body shape will change. For example, a girl’s hips will widen.
- The external genitals (vulva) and pubic hair will start to grow. Pubic hair will get darker and thicker over time.
Around 12-14 years (about two years after breast development starts)
- Hair will start growing under the arms.
- A clear or white discharge from the vagina starts several months before periods start. If the discharge bothers your child, you could suggest your child uses a panty liner. If your child says it’s itchy, painful or smelly, consult your GP.
- Periods will usually start within 2 years of breast growth starting, but can take up to 4 years.
Boys: key physical changes in puberty
In boys, these are the main external physical changes in puberty that you can expect.
Around 11-12 years
- The external genitals (penis, testes and scrotum) will start to grow. It’s normal for one testis to grow faster than the other. You can reassure your child that men’s testes usually aren’t the same size.
- Pubic hair will start to grow. It will get darker and thicker over time.
Around 12-14 years
- Your child will have a growth spurt. Your child will get taller and their chest and shoulders will get broader. Some parts of your child’s body – like their head, face and hands – might grow faster than their limbs and torso. This might result in your child looking out of proportion for a while. On average, boys grow 10-30 cm. They usually stop growing at around 18-20 years.
- It’s common for boys to have minor breast development. If your child is worried by this, it might help your child to know it’s normal and usually goes away by itself. If it doesn’t go away or if the breasts seem to be growing a lot, consult your GP.
Around 13-15 years
- Hair will start growing on other parts of your child’s body – under the arms, on the face and on the rest of the body. Leg and arm hair will thicken. Some young men will grow more body hair into their early 20s.
- The hormone testosterone is produced, which stimulates the testes to produce sperm.
- Your child might start having erections and ejaculating (releasing sperm). During this period, erections often happen for no reason at all. Just let your child know that this is normal and that people don’t usually notice. Ejaculation during sleep is often called a ‘wet dream’.
Around 14-15 years
The larynx (‘Adam’s apple’ or voice box) will become more obvious. Your child’s larynx will get larger and their voice will ‘break’, eventually becoming deeper. Some boys’ voices move from high to low and back again, even in one sentence. This will stop in time.
Other physical changes in puberty: inside and out
Teenage brain development affects your child’s behaviour and social skills. Your child will begin to develop improved self-control and skills in planning, problem-solving and decision-making. This process will continue into your child’s mid-20s.
Bones, organs and body systems
Many of your child’s organs will get bigger and stronger. Lung performance improves, limbs grow, and bones increase in thickness and volume.
Because children grow so fast during puberty, their centres of gravity change and their brains might take a while to adjust. This might affect your child’s balance. You might see a bit more clumsiness for a while, and your child might be more likely to be injured.
Muscles increase in strength and size during this period. Your child’s hand-eye coordination will get better over time, along with motor skills like ball-catching and throwing.
Your child will gain weight and need more healthy food. Teenagers’ stomachs and intestines increase in size, and they need more energy, proteins and minerals. Foods with plenty of calcium and iron are important for bone growth and blood circulation.
Sleep patterns change, and many children start to stay awake later at night and sleep until later in the day.
A new type of sweat gland in the armpit and genital area develops during puberty. Skin bacteria feed on the sweat this gland produces, which can lead to body odour. Hygiene is important.
Skin and hair
Glands in the skin on the face, shoulders and back start to become more active during puberty, producing more oil. This can lead to skin conditions like acne. If you’re concerned about your child’s skin, first check whether the pimples or acne are worrying your child too. If they are, consider speaking with your GP.
Children might find their hair gets oilier, and they need to wash it more. This is normal.
Children will get their second molars at around 13 years of age. Third molars – ‘wisdom teeth’ – might appear between 14 and 25 years. These teeth can appear in singles, pairs, as a full set of 4 wisdom teeth – or not at all. Healthy teeth and gums are vital to your teenage child’s health, so teenage dental care is important.
Puberty and children with additional needs
Children with additional needs are likely to go through the physical changes of puberty in the same way as other children.
Some children might have delayed physical development because of chronic health problems, which might cause a delay in the onset of puberty. How your child manages puberty emotionally might also be affected by additional needs. A health professional can answer any questions you have about this. Your GP or other health professionals working with your child can help.
You might like to read more about preparing autistic children for puberty, preparing autistic girls for periods and helping autistic teenagers learn about personal hygiene.