What are the testicles?

There are two testicles which lie in the scrotal sac (scrotum). Each testis contains tightly coiled tubes, seminiferous tubules, within which the germ cells (reproductive cells) divide and mature to form sperms. Sperms are stored in the epididymis and carried from there, through the spermatic cord, to the penis to be ejaculated during sex. Sperms are formed from puberty onwards

The testicles also produce the hormone testosterone, which causes changes in young men, such as deepening of the voice and growth of a beard. In the area around the testicles and in the abdomen, there are many lymph nodes and vessels. These drain fluid from the tissues back into the bloodstream.

What causes testicular cancer?

The cause of testicular cancer isn’t known, although it is more common in men who have had an undescended testicle. Before birth the testicles develop inside the baby’s abdomen and later descend (move down) into the scrotal sac. This usually happens at birth or during the first year of life. If it doesn’t happen to both testicles, a man has a higher risk of developing testicular cancer

Testicular Cancer doesn’t usually run in families. However, in a small number of cases, several men in one family have developed the disease. This may mean that it can be inherited, that is passed from one generation to the next. Studies are being carried out with these rare families, to try to identify a gene which may increase the risk of developing testicular cancer.

There is no evidence that testicular cancer is caused by injury, sexual activity or aspects of lifestyle, for example diet, smoking or stress


The most common symptom of testicular cancer is a lump, hardening or swelling of the testis which may or may not be painful. An ache or “dragging” sensation in the scrotum is another symptom which should not be ignored

Constant backache, breathlessness or development of breasts should be reported to your doctor. Although there may be other reasons for these symptoms, all of them could mean that the cancer has spread.