Once you have reached puberty, it is a good idea to regularly check the size and shape of your testicles. A good time to do this is in the shower.

The purpose of this check is to get to know the size, shape and texture of your testicles. It is perfectly normal for one of your testicles to be bigger than the other. But if you notice any changes in your testicles, especially a lump, you must see a doctor. One of the most common cancers for men between the ages of 15 and 30 years is cancer of the testes.

Testicular cancer is the most common cancer in young men – and the good news is it’s extremely curable. If you feel a swelling or lump, it’s important to get it checked out (though most lumps won’t be cancer). A heavy feeling in your balls can also be a warning sign.

Balls

During puberty, there is a change in the functioning of your testicles (testes), which is caused by your body’s production of the male hormone testosterone. This means that your testicles begin to produce sperm.

Sperm are shaped like a tadpole with ‘tails’ that enable the sperm to move. Sperm are so tiny that they can only be seen under a microscope. (how many sperm can a man produce? the average male will produce roughly 525 billion sperm cells over a lifetime – A healthy adult male can release between 40 million and 1.2 billion sperm cells in a single ejaculation.)

Testicles need to be kept cool to promote normal sperm development. This is why they hang outside the body in a sac (bag) called the scrotum. It is quite normal for one testicle to be larger or to hang lower than the other.

At birth, some boys may have experienced what is called ‘undescended testicles’ where one or both testicles fail to move down into the scrotum. This is usually corrected after birth.

Testicles that have moved down into the scrotum will sometimes pull back into the body, for instance in cold water. This is quite normal. They will eventually move back into place on their own.

Any concerns you have about differences in the testicles can be talked over with a doctor.