A varicocele is when the veins in the scrotum (the pouch that holds the testicles) become bigger and swollen. These veins carry blood from the testicles, but sometimes the blood doesn't flow properly and backs up, causing the swelling. It's similar to varicose veins you might see in people's legs.

Varicoceles are common in boys who haven’t gone through puberty yet, and teenage boys. They are not usually found in boys under age 10, and it’s rare for them to form after the teenage years. Most varicoceles are found only on the left side because of the way blood drains from the left testicle. In some cases they can also form above the right or in both testicles.

Varicoceles can be grouped into three types based on how visible or painful they are:

The varicocele is small and can only be felt when standing and putting pressure on the belly. It usually doesn't cause pain or irritation.
The varicocele is a bit bigger and can be felt more easily, even without any pressure. It might cause some soreness but isn't usually too painful.
The varicocele is large, easy to feel, and may even be visible. It can cause soreness or pain.

In some cases, varicoceles can affect a man’s ability to have children later in life by slowing blood flow and raising the temperature of the testicles. This can cause the testicles to make less sperm, and the sperm that is made may not be healthy. However, most boys with a varicocele will have no fertility problems later in life.

Which applies to you?