Puberty and sexual development
Puberty is the time when a child's body becomes able to reproduce. It usually starts between about 8 and 14 years and takes several years. The brain (hypothalamus and pituitary) sends signals to the ovaries or testes, which make hormones: mainly oestrogen and progesterone, or testosterone.
- Changes for everyone: growth spurt, body hair, sweat and acne, stronger feelings and mood swings, new attractions.
- Often in girls: breasts develop, hips widen, periods (menstruation) begin.
- Often in boys: voice deepens, shoulders broaden, testes start producing sperm.
Everyone's timing is different. Good hygiene, sleep, food and talking to a trusted adult help.
Sexuality across life and identity
Sexuality is a normal part of being human at every age. It is much more than sex: it includes the body, feelings, attraction, identity, relationships, values and respect.
- Sex (biological): body features at birth.
- Gender: roles and expectations a society links to being male or female, and a person's own sense of their gender (gender identity).
- Sexual orientation: who a person is attracted to.
Healthy relationships at any age are built on respect, trust, honesty, equality and the freedom to say no. Every person deserves dignity, whatever their identity.
Body image and the media
Body image is how you see, think and feel about your body. During puberty bodies change fast, so worries are common.
Media and social media often show bodies that are filtered, edited, posed or very rare. Comparing yourself with them can lead to low self-esteem, unhealthy dieting or eating disorders.
Helpful habits: remember images are edited; follow accounts that show real people; focus on what your body can do; eat well, sleep and move; never tease others about their bodies; talk to someone if worries take over.
Consent, rights and the social context
Consent is agreeing to something freely, clearly and with full understanding. It must be given every time, can be withdrawn at any moment, and is not possible if a person is pressured, scared, asleep, drunk or below the legal age. Silence is not a yes.
Resisting pressure: say no clearly, use body language, leave, and tell a trusted adult. Real friends accept no.
Sexual and reproductive rights (recognised by the WHO and many laws) include: correct information and education, bodily integrity and privacy, choosing whether and when to have a relationship or children, freedom from violence, forced marriage and discrimination, and access to health care. Laws in every country protect children from abuse; culture, religion, family and laws shape how these rights are lived.
Sexually transmitted infections (STIs) and prevention
STIs are infections passed mainly through sexual contact and some body fluids.
- Bacterial (curable with antibiotics): chlamydia, gonorrhoea, syphilis.
- Viral (treatable, not always curable): HIV, HPV, herpes, hepatitis B.
Many STIs have no symptoms, yet can cause infertility, cancer or serious illness if untreated. HIV is not spread by hugging, sharing food, toilets, tears or mosquitoes.
Prevention: abstinence or delaying sex, using condoms correctly, vaccines (HPV, hepatitis B), regular testing, early treatment, never sharing needles. For HIV, medicines can also prevent infection (PrEP) and keep people healthy.
Reliable information: doctors, nurses, school counsellors, official health websites. Check who wrote it, the evidence and whether it is selling something.
Key formulas and definitions
- Sexual health = physical + emotional + social well-being about sexuality
- Puberty: brain → hormones (oestrogen/progesterone or testosterone) → body changes
- Consent = free + clear + informed + reversible + every time
- Bacterial STIs: chlamydia, gonorrhoea, syphilis (antibiotics)
- Viral STIs: HIV, HPV, herpes, hepatitis B (vaccines for HPV and hepatitis B)
- Prevention: abstinence, condoms, vaccines, testing, early treatment
Worked examples
1. Riya, 10, has started her periods; her friend Meera, 13, has not. Is something wrong?
No. Puberty starts at different ages, roughly 8–14. Both are normal. If worried, they can talk to a doctor or trusted adult.
2. A friend says, "Everyone online looks perfect, I hate my body." How can you help?
Remind them that many images are edited or filtered, that real bodies differ, focus on what they like and can do, and suggest talking to a trusted adult if the feeling stays.
3. Someone says yes to holding hands, then pulls away. What should the other person do?
Stop. Consent can be withdrawn at any time, and a pulled-away hand or hesitation means no.
4. Why is the HPV vaccine given around ages 9–14?
It works best before any possible exposure to the virus, and young people make a strong immune response.
5. A classmate refuses to sit next to a student with HIV. Is that justified?
No. HIV does not spread by sitting together, touch, sharing food or toilets. It is discrimination; the student has the same right to education.
Common mistakes
- Thinking sexuality is only about sex. It includes identity, feelings, relationships and values.
- Thinking someone with an STI always looks sick. Many STIs have no signs; only a test tells.
- Thinking silence or no answer means yes. Consent must be clear and freely given.
- Trusting any website or video. Check the source, evidence and whether it is selling something.