The testicles (or Balls) are the two oval-shaped male sex organs that sit inside the scrotum on either side of the penis. The testicles are an important part of the male reproductive system because they produce sperm and the hormone testosterone, which plays a major role in male sexual development

Most men’s testicles are about the same size, though it’s common for one to be slightly bigger than the other. It’s also common for one testicle to hang lower than the other one.
The testicles should feel smooth, without any lumps or bumps, and firm but not hard. You may feel a soft tube at the back of each testicle, which is called the epididymis.

Cancer of the testicle is one of the less common cancers and tends to mostly affect men between 15 and 49 years of age.


The most common symptom is a painless lump or swelling in one of the testicles. It can be the size of a pea or it may be much larger.

Other symptoms can include:

  • a dull ache in the scrotum
  • a feeling of heaviness in the scrotum
  • It’s important to be aware of what feels normal for you. Get to know your body and see your GP if you notice any changes.
If you notice any changes or anything unusual about your balls, you should see your GP.