• STI postal kits are currently delayed due to a temporary postal issue. Please allow up to 21 days for test kits to arrive.  Chlamydia & Gonorrhoea test kits can be picked up from main reception at Unity Central Health Clinic between 09:00 and 16:00 If you urgently need a blood test, or have symptoms, please call 01173426900

Male body

Here are some common questions asked by teenagers about their bodies.


  • At what age do you go through puberty?

    Puberty describes all the physical changes that children go through as they grow into adults. Changes start to occur at around 11 years old, but there’s no right or wrong time to start puberty. It might be sooner or it might be later, and this is normal.

  • What's the average penis size?

    Penis size varies from man to man, in the same way that everyone is a different height, weight and build. Penises are somewhere around 9cm (3.75in) long when they’re not erect, but it’s normal for them to be shorter or longer than this. Some things can make your penis temporarily smaller, such as swimming or being cold.

    Penises are roughly the same size when they’re hard, between about 13 and 18cm (6-7in) long. You can’t make your penis larger or smaller with exercises or medication.

  • What is circumcision?

    Circumcision is an operation to remove the piece of skin (the foreskin) that covers the tip of the penis. In the UK, it’s usually done for religious reasons, and is most common in the Jewish and Muslim communities. If you have been circumcised, it’s nothing to worry about. It won’t affect your ability to have sex.

    Female circumcision (more correctly termed female genital mutilation or FGM) is illegal in the UK. It involves cutting off some or all of a girl’s external genitals, such as the labia and clitoris. It is NOT the same as male circumcision which has health benefits. There are no medical benefits to FGM.

    For further information you can visit the following websites:

    Daughters of  Eve

    Desert Flower Foundation

    Integrate Bristol

    Forward UK



  • I have spots on my penis and it itches. Is this normal?

    If you’ve recently had sex without using a condom you may have picked up a sexually transmitted infection. Visit a Unity Clinic to get tested and talk to someone.

    Lots of boys have normal lumps and bumps on their penis, and spots can also be caused by an allergy or irritation. But if you’re worried, seek advice from a doctor or clinic. Medical people see problems like this every day, so there’s nothing to be embarrassed about.

  • Is it normal for my penis to smell fishy and have white bits behind the tip?

    This can happen naturally from time to time. To prevent it happening, wash gently behind the foreskin if you have one (men who have been circumcised don’t have a foreskin) when you bath or shower. Use water, or water and a mild soap.

    If you’re washing carefully and the symptoms don’t go away, and you’ve had sex without a condom, you may have an STI. Visit a Unity clinic to get tested and talk to someone.

  • What is sperm?

    Sperm is produced in the testicles (balls) and released in fluid called semen during sexual activity. Every time a man ejaculates (comes) he can produce more than 100 million sperm. But it only takes one sperm to get a girl pregnant, and that can happen before the boy ejaculates. This is because the fluid that comes out of the tip of his penis before he ejaculates (called pre-ejaculatory fluid) can contain sperm.

    If you’re having sex with a girl, always use contraception and condoms to prevent both pregnancy and STIs. Talk to your partner about what contraception she’s using, and make sure that you use condoms too.

    If you’re having sex with a boy, always use condoms to stop yourself getting an STI or passing one on.

  • Is it normal to get an erection when you wake up in the morning?

    Yes, many boys and men have an erection when they wake up in the morning, and they can get one when they’re not expecting it during the day, even when they’re not sexually excited. This is a normal part of sexual development and growing up.

  • Is it normal for one testicle to hang lower than the other?

    Yes, this is normal and nothing to worry about. One theory is that it stops your testicles banging together when you run.

  • How do I know if I have testicular cancer?

    Check your testicles every month by gently rolling them, one at a time, between your thumb and fingers to feel for any unusual lumps or bumps. You’ll feel a hard ridge on the upper back of each ball. This is the epididymis, where sperm is stored, and it’s normal to feel it here.

    If you feel any lumps, it probably isn’t cancer, but get it checked by a doctor. Other warning signs include:

    • one ball growing larger or heavier than the other
    • an ache in your balls
    • bleeding from your penis.

    If you notice any of these, see your doctor. If caught early, testicular cancer can usually be treated successfully.

  • What is premature ejaculation?

    This is when a boy or man ejaculates (comes) too quickly during sex. This is fairly common, especially among younger men, and can be due to nerves or over-excitement. Some people don’t worry about it, and some find that using a condom can help to delay ejaculation.

    If it bothers you, see your local doctor, nurse, or visit a Unity Clinic. These places will give you free and confidential advice whatever your age, even if you’re under 16.

  • What if I have problems getting an erection or keeping it up?

    There are lots of reasons why you might not be able to get an erection, or keep one. For some people the problem is physical but for others it can be psychological. Imagine if you are really under pressure to have sex or to do sex well, you’re more likely to be so nervous you can’t actually get an erection at all.

    For more people, these issues are temporary and it might be as simple as doing some relaxation techniques.  It is always best to speak to someone if you are worried. All Unity services are confidential, free and open to anyone 13-24 so don’t be scared to talk about the issue – we’ve probably heard it all before!

    You could go to a Unity doctor, speak to someone at a sexual health clinic or drop into your school Brook service.

    Check out the NHS Choices video on this problem:


  • Can you pee while having sex?

    No. During sex, a valve shuts the outlet tube from your bladder so that only sperm can pass through the tube (urethra), which you use to pee.

  • Why is it harder to ejaculate when you have sex a second time soon after the first?

    If you have sex a second time straight after the first, it can take longer for you to reach orgasm (come). This is normal. If you’re worried about this, take a longer break after sex before you start again. Whether it’s the first, second or tenth time you’ve had sex that day, always use a new condom to protect against pregnancy and STIs.

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