One of the most common questions asked by men before treatment for testicular cancer is whether their sex life or fertility will be affected.

The important thing to remember is that, if the other testicle is healthy, the removal of one testicle will not affect your sexual performance or your ability to father children. This is because the remaining healthy testicle will produce more testosterone and sperm to make up for the removal of the affected testicle.

Chemotherapy treatment for men with testicular cancer commonly causes infertility during treatment and for a time after. This is usually temporary but your doctor will advise that you consider storing sperm before having treatment. The rate at which the sperm count recovers varies from person to person, but it generally returns to normal from around 18 months or so after treatment. In men having high-dose chemotherapy, the risk of infertility is higher.

The effect of chemotherapy on semen (the liquid that contains the sperm) and sperm is uncertain. Condoms should be used during sex within the first 48 hours after chemotherapy to protect your partner from any of the drug that may be present in semen. Although there is no evidence that chemotherapy can harm children fathered after the treatment has finished, doctors usually advise you to avoid conceiving a child for about a year after treatment.

Some men with testicular cancer have a low sperm count before they start any treatment, and sometimes successful treatment with chemotherapy may actually cause the sperm production to improve.

Sometimes it is necessary to surgically remove lymph nodes in the abdomen (retroperitoneal lymph node dissection), if they are still enlarged after radiotherapy or chemotherapy. Unfortunately, this can affect fertility, as the operation can damage the nerves that control the discharge of sperm through the penis (ejaculation). However, new surgical techniques mean that this problem can usually be avoided. If there is a possibility that you may need such surgery, and if you are fit enough to produce sperm samples for storage before treatment starts, some of your sperm can be stored.

Although this further surgery may make it more difficult for you to father a child, it will have no physical effect on your ability to get an erection or have an orgasm.

Radiotherapy does not normally cause infertility. However, a small dose of radiation does reach the remaining testicle. There is no evidence that this radiotherapy has any effect on children fathered after the treatment, but men are usually advised to use effective contraception for 6-12 months after treatment has ended.

Any course of treatment may make you too tired to be interested in sex, and lower your sex drive. This is common to many illnesses, not just cancer. It is worrying, but remember that it is a temporary side effect. Once the treatment is over and your body begins to return to normal, your sex drive (libido) will also return.

Sexual problems are very personal - and important. Talking about them can be a great help.

Although this can sometimes be difficult, once they have summoned up the courage to talk openly to their partners, many men find that their fears of rejection are unfounded. Sexual relationships are built on many things including love, trust and common experiences. You may even find a new closeness after talking through a problem with your partner.

In some cases your doctor or nurse or a close friend or relative may also be able to offer help and advice. Some hospitals have nurses or social workers who have been specially trained to help people with sexual problems.

We have a section on sexuality and cancer which you may find helpful.

One common fear is that cancer cells can be passed on to your partner during sex. This is not true. Cancer is not infectious and it is perfectly safe for you to have sex.