What is puberty?
Between the ages of 10 and 14 most boys and girls begin to notice changes taking places to their bodies. These changes which take place over a number of years also include emotional changes and are sometimes referred to as puberty.
One of the main physical changes of puberty is the growth and development of the sex organs. Boys and girls both have sex organs that are outside the body and can be seen. They also have sex organs inside the body. Those on the inside are usually called the reproductive organs, and those on the outside the genitals. Two of the main sex organs in a girl's body are the vagina and ovaries. In a boy's body two of the main sex organs are the penis and testicles.
Some more about a girl's sex organs
The opening to the vagina is one of three small holes that a girl has between her legs. At the front is the urethral opening which a girl urinates (wees) through. The anus is the opening at the back where she defecates (poos) from.
From the vaginal opening in the middle there is a passageway or tube called the vagina which leads to a girl's internal sex organs. When a girl has her period the blood comes out through her vagina.
Inside the vagina is a thin skin called a hymen. The hymen partly covers the vaginal opening, but there is still enough of a gap for blood to get through.
Another important sex organ is the clitoris. This is about the size of a pea and it is at the front of a girl's outside sex organs. The outer lips (labia) of a girls sex organs, the clitoris and the vaginal opening are together known as the vulva.
Some more about a boy's sex organs
The boy's sex organs outside his body are his penis and testicles (testes).
A boy's penis hangs down between his legs at the front of his body. The main part of the penis is called the shaft. The end of the penis is called the glans. The foreskin is skin that covers the glans. Usually it can be pulled back quite easily. If it is tight it can be stretched by gently pulling it over the glans. All boys are born with a foreskin, but some have it removed whilst they are a baby. This removal of the foreskin is called circumcision.
The scrotum is a loose wrinkly pouch of skin that hangs down behind a boy's penis. It contains the testicles (testes). As a boy goes through puberty his testicles move lower down his scrotum. One of the testicles usually hangs lower than the other.
Eggs and sperm
A girl has two ovaries inside her body. These ovaries contain a girl's sex cells or eggs. During puberty the ovaries begin to release eggs. Usually they will release one egg every month. These eggs are very small, each one being no bigger than the head of a needle.
A boy's sex cells are called sperm and they are even smaller than a girl's eggs. At puberty a boy's testicles will start making sperm. Sperm leaves a boy's body through his penis, usually when it is hard and erect. This is known as ejaculation. When a boy ejaculates millions of tiny sperm are sent from his testes up through his penis and out through the end.
When sperm from a boy meets up with an egg from a girl they can join together, and from this a baby grows. This joining is sometimes called fertilisation.
How do sperm and an egg meet? - Sexual intercourse
Sperm and an egg can meet when a boy and a girl have sexual intercourse. Sexual intercourse is when a boy's hard penis goes inside a girl's vagina, and he then ejaculates sperm through his penis.
A boy is physically able to become a parent when he first starts to ejaculate sperm. A girl is physically able to become a parent when her ovaries start to produce eggs.
What happens to an egg if it meets with any sperm?
When an egg is released from a girl's ovaries it travels down inside one of her fallopian tubes towards the uterus or womb. Whilst this is happening the uterus starts to get ready for a fertilised egg by developing a thick lining. If the egg is fertilised on the way, then it settles in the uterus and this is where the baby starts to develop.
What happens to an egg if it does not meet with any sperm?
When the egg is not fertilised, there is no need for the thick lining of the uterus. The lining slowly begins to come away and flows through the cervix or "neck" of the uterus which connects the uterus to the vagina. It then comes out of the girl's body through the vagina. This is the blood that comes out when a girl has her period. As soon as a girl starts to have her period her ovaries start getting ready to release another egg. The length of time between one period and the next is the menstrual cycle.
What are the main physical signs of sexual feelings?
The main sign for boys that they are getting sexually excited is when they get erections.
The main sign for girls is when their vagina begins to get moist. The clitoris gets bigger too.
For both boys and girls when they are sexually excited or "turned on", extra blood comes to the surface of the skin, particularly around the penis and vagina. You can feel warm and sensitive and sexy just about anywhere on your body.
At what age do boys and girls start to get sexual feelings?
A person can have sexual feelings any time in their life, but these change around puberty. You might find some sexual feelings just seem to happen to you. But sexual feelings mostly come about from things you choose to do, either on your own or with someone else.
A main way that people express their sexual feelings is by touching their own genitals. This is called masturbation. Some people don't masturbate at all, or hardly ever. Other people masturbate every day. Masturbation does not cause you any harm.
Some girls enjoy touching their clitoris. Many boys enjoy touching their penis, particularly the tip.
When a person is masturbating they become more and more sexually excited. They may then reach a peak of sexual excitement which is called having an orgasm or "coming". This is when all the tension and excitement that has built up is suddenly released. Boys ejaculate when they have an orgasm and their penis will then go limp.
For many people masturbation is their first sexual experience. Some people refer to masturbation as playing with yourself, or, especially with boys, jerking off, a hand job, or wanking.
Sexual feelings in relationships
When people have sexual feelings for each other they will usually want to do sexual things together. There is no set time or order in which to do things.
They often want to kiss and cuddle and hold hands. When people kiss they sometimes 'French kiss'. This is when both people open their mouths when they are kissing and their tongues touch together.
People also like to touch each other through their clothes or put their hands inside to stroke or touch each other's genitals.
There are a variety of other sexual activities that people will also do including sexual intercourse.
It can seem natural to bring sexual feelings into a relationship. But it can also change how people feel about each other and about themselves. You might want to do something because you feel curious about it. Or because you think it will make you feel good. And you might want to do it because you feel very close to someone.
But it's important not to do any of these things because you feel under pressure. And that you think about the consequences and how you'll feel afterwards.
Sexual intercourse
Sexual intercourse is when a boy's hard penis goes inside a girl's vagina. This is often called having sex or making love. For many people this can be the most important sexual thing they can do with someone. It can be very enjoyable and fulfilling. For some people it can be the way they can most show their love for each other.
But there are a lot of things to consider. A girl can become pregnant from having sexual intercourse. There are also infections that boys and girls can get if they have sexual intercourse with a person who already has the infection. These are called sexually transmitted infections or diseases. A person can't always tell if they've got one.
You also need to think about your feelings and what you believe. If you have sex because you were pressurised, were drunk or were just curious to know what it would be like, then you may regret it later.
You also need to consider the law. In England it is against the law for a boy to have sexual intercourse with a girl who is under 16.
Pregnancy
If a boy and a girl have sexual intercourse the girl can get pregnant.
She can become pregnant even if:
- She has not had her first period;
- The boy withdraws his penis from her vagina before he ejaculates;
- She is having her period;
- It is the first time she has had sexual intercourse.
The first sign that a girl may be pregnant is that her period does not start when she expects it to. If this happens then it is very important to see a doctor or talk to some other adult as soon as possible.
Contraception can be used to prevent pregnancy occurring when a boy and girl have sexual intercourse. Some contraceptives, like the contraceptive pill, are used by girls. Boys can use condoms. Condoms also prevent sexually transmitted infections from being passed from an infected person to another person during sexual intercourse.
Help and Advice
Puberty is a time when you are going through many emotional and physical changes. There may be times when you feel concerned about what is happening to you or how you feel. It can be really hard to do, but it can really help to talk to other people.
It can be really helpful to talk to your parents or guardian. If you can't, or as well as talking to them, there are other people who can help. You might be able to talk to someone at school, either a teacher or another adult.
For more about puberty, sex and sexuality, see our teens section.
For answers to frequently asked questions, see our sex FAQ section.
AVERT.org also has a list of sources of help and advice.