Is it normal to have one testicle bigger than the other?

Short answer: Yes. It is perfectly normal for guys to have one testicle that’s larger than the other one. Usually the testicle on your right is a little larger than the left, and one testicle (usually the left one) will often hang a bit lower than the the other. So when someone asks ‘how’s it hanging’, ask them to be more specific; left or right?
If your testicle has suddenly become larger or decreased in size though you should see a doctor.

There’s no question that testicles aren’t exactly the most aesthetically pleasing things. It’s a safe bet you’ve never heard a woman praise a guy for having a beautiful scrotal sack. They look a bit like an upside down krang (with a tan).
But you should take time to have a good look at your testicles once a month to catch any changes.

How to examine your testicles:

Loosen up your scrotum in a warm bath or shower.

Cup your scrotum with your hand and gently rub one testicle at a time between your thumb and pointer finger. Your testicles should feel smooth and oval shaped.

Check out this excellent video from Embarrassing Bodies on how to examine your testicles.

If you notice any change in the size of your testicles or any lumps or pain, see a doctor.

Some of the things that can cause painful or swollen testicles include:

• Fluid can collect in an area around a testicle (hydrocele)
• Infections from a virus or a sexually transmitted disease.
• Injury to the testicles, such as from being kicked, hit, or crushed. (hint: punching each other in the testicles for fun is not a good idea)
• Swelling in a vein that drains blood away from a testicle (varicocele)
• Testicular cancer.
• Testicular torsion (when a testicle gets twisted)

If you think you have a twisted testicle (testicular torsion) see a doctor as soon as possible. This can be serious.

For younger guys a trip to the doctor that requires having your testicles examined can be daunting, but remember whatever you’ve got going on down there your doctor has seen before and probably a lot worse.

Also note: be prepared for your penis to misbehave when you visit the doctor. For some reason the penis often decides to decrease to about 1/3rd it’s normal size leading to ‘doctor willy syndrome’. Doctors see it every day. So don’t go home thinking your doctor is going to tell all his mates about ‘the guy with the tiny penis’ he examined today. If you’re overly concerned about what your doctor thinks about your junk, when you drop your pants give your penis a quick downward pull. That should buy you a few seconds where the doctor will see you have a somewhat normal sized penis before it turtles up again.