Do you have a mass in your testicles that feels like a bag of worms when you're standing up, but goes away when you sit down? Get thee to a doctor's office.
You're probably familiar with varicose veins -- swollen or knotted veins that are most commonly present in the legs. Think of varicoceles as another version of that -- one that makes your scrotum feel like it's full of spaghetti. The condition is an enlargement of the veins inside the scrotum that transport oxygen-depleted blood back to the heart. The valves in the veins have failed, and blood builds up where it shouldn't.
The pain can be mild or severe, and tends to grow worse over the course of a day. As the varicoceles grow in size, they will become easier to identify. Due to the positioning of the veins and testicles, the overwhelming majority of varicoceles occur on the left testicle.
Fortunately, varicoceles are fairly easy to treat through either the use of doctor-prescribed anti-inflammatories or through minor surgery that removes obstructed veins.