Doctor reveals the number one cause of male infertility and how to treat it

A doctor has revealed one of the most common causes of infertility in men and how it can be treated.

While in women fertility commonly drops off in the mid to late thirties, though not always, men can theoretically remain fertile for their whole life notwithstanding having any health complications.

But there are problems that men can face which might result in them not being able to have children.

Some might have a low sperm count, or their sperm are not very strong meaning that they struggle to fertilize an egg.

And while men can remain fertile for life, there are changes that happen to their bodies as they age which affect their fertility.

For example, the amount of semen in an ejaculation might be less, and the force of ejaculation might also not be as strong, both of which decrease the chances of a baby.

There are a lot of treatments available for people who are struggling to conceive (Maskot/Getty)

Writing in the New York Post, specialist Dr. Bobby Najari highlighted one condition in particular is called varicocele, and can affect as many as one in five men during their lifetime.

The condition is most often diagnosed during adolescence, and also accounts for two out of five couples who are having trouble conceiving a child.

Varicocele is a similar condition to varicose veins, but it happens around the genitals rather than the legs.

It means that blood vessels in the scrotum swell, which can have a number of knock effects in fertility.

The swollen vessels can impact on the production of sperm, lowering sperm count, and also reduce the movement of sperm as well.

Due to the impact of this condition, if you are consulting a fertility specialist and have varicocele it's important to let your fertility doctor know.

Dr. Najari explained that the condition is treatable.

Cleveland Clinic says in milder cases ice packs as well as over-the-counter medicine can be used, and you should consult a medical professional if you are concerned.

The condition makes up two out of five couples struggling to have a baby (RealPeopleGroup/Getty)

In serious cases it is also possible to have a varicocelectomy to remove varicoceles which are particularly painful or affecting fertility, Dr. Najari wrote.

While varicocele can affect fertility, it can also cause some pain or discomfort in more severe cases.

Cleveland Clinic outlined that it's not exactly clear how the condition is caused, but one theory is about a 'switch' which is located inside certain veins in the spermatic cord - the band of tissues keeping the testicles in place.

The valve has two structures which help move blood in and out of the testes, and if it doesn't work the way it's supposed to, this may lead to swelling.

If someone is worried about their fertility being affected, then they also have the option to freeze sperm to guard against any future challenges with having children, which can then be used for in-vitro fertilization if necessary.