Cancer and its treatment can cause physical changes that may affect your sex life. Find out about male and female anatomy and what happens during sex.

About the body and sex

Cancer or its treatment may cause changes to your body that can affect your sexual well-being.

This information is about the parts of the body that are involved in wanting and having sex. It also explains what happens to the body during sex. If you have had gender realignment surgery or are intersex, your body may be different in some ways to what we describe here. If you cannot find the right information, your GP or local sexual health service may be able to help.

The brain and nerves

The brain controls how the body works. For example, it controls breathing, blood pressure and heart rate. It also controls how we understand the world around us, and our emotions, thoughts and memories.

Nerves are cells that send messages between the brain and different parts of the body. They give the brain information about what is happening in an area. For example, this may be whether something feels painful or good. The nerves also allow the brain to send instructions to that area of the body. For example, this might be an instruction to move away from the cause of the pain.

When it comes to sex, the brain and nerves tell you what feels good. This depends on what you are feeling physically. It also depends on things such as your emotions and memories. Your brain and nerves also help control what happens to your body during sex.

The female pelvic area

The pelvis is the area between the hips and below the tummy-button.

The ovaries, fallopian tubes, womb, cervix and vagina are inside the body in the pelvis. Together, these are called the reproductive system. This is the system involved in getting pregnant and giving birth.

Female reproductive organs 

The brain controls the reproductive system using hormones (chemical messengers). These hormones are made in the ovaries and in areas of the brain such as the pituitary gland. The hormones affect your periods (menstruation) and ability to get pregnant (fertility). They also affect your interest in sex (your sex drive or libido).

Eventually the ovaries stop making hormones. This is called the menopause and usually happens between the ages of about 45 and 55. Changing levels of hormones during the menopause can cause symptoms that include lack of interest in sex and vaginal dryness.

Outside the body and between the legs is the vulva. The skin forms two large outer folds and two smaller inner folds around the opening to the vagina. At the front of the vulva is the outer tip of a sensitive structure called the clitoris. The rest of the clitoris sits further back and inside the body.

The vulva 

The pelvis also contains:

  • the bladder and urethra – the system that removes urine (pee) from the body
  • the lowest end of the bowel, including the rectum and anus – the system that removes stools (poo) from the body
  • a set of supporting muscles called the pelvic floor muscles.

The male pelvic area

The pelvis is the area between the hips and below the tummy-button.

Outside the body, the penis hangs from the front of the pelvic area. Behind the penis, two testicles hang below the body in a pocket of skin called the scrotum. A gland called the prostate sits inside the body in the pelvis.

Together the penis, testicles and prostate gland are called the reproductive system. This is the system that allows you to make sperm and start a pregnancy.

The brain controls the reproductive system using hormones (chemical messengers). These hormones are made in the testicles and in areas of the brain such as the pituitary gland. The hormones control sperm production and your ability to get and keep an erection. They also affect your interest in sex (your sex drive or libido).

The pelvis also contains:

  • the bladder and urethra – the system that removes urine (pee) from the body
  • the lowest end of the bowel, including the rectum and anus – the system that removes stools (poo) from the body
  • a set of supporting muscles called the pelvic floor muscles.

Diagram of male reproductive floor labelled

Other sensitive areas

Most people also have other areas of the body that are sensitive to touch. These can be an important part of their sex life. They are sometimes called erogenous areas. Sensitive areas vary from person to person. They may include:

  • the chest area, breasts or nipples
  • the back of the neck
  • the anus and rectum
  • the backs of the knees, buttocks or inner thighs.

 

What happens to the body during sex

Your body may go through various stages. This is sometimes called the sexual response.

Arousal

This is when you feel ‘turned on’ and ready for sex. You may feel aroused by thinking about sex, seeing someone you are attracted to, touching someone or being touched by someone. During this stage, your brain usually sends messages to the nerves in your pelvis and increases the blood flow to these areas. This can cause:

  • the vulva and vagina to swell and become wet
  • the penis to become hard (erect).

Plateau

This is a stage of arousal where your body is very sensitive to touch.

Orgasm

This is a feeling of intense pleasure that may happen after being aroused. It is also called climax or ‘coming’. Muscles in different areas of your body contract. Fluid (ejaculate) may release from the tip of the penis. Orgasm can happen by touching the penis or clitoris. Some people can reach orgasm without this or by touching other parts of the body.

Resolution

This is the stage after arousal and orgasm. The physical changes in the body go back to normal. Some people can become aroused and orgasm again straight away. Others may not want or be able to for a time. In general, this takes longer as we get older.

Sexual response is different for each person. What feels good for you depends on:

  • how your brain responds to a physical sensation
  • how you feel emotionally
  • your memories, beliefs and experiences.

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