First, do a visual exam. Standing in front of a mirror, look for any signs of swelling in the skin of your scrotum. Second, feel each testicle for any unusual lumps or swellings. Examine your other testicle in the same way. Don't be surprised to discover that one testicle is slightly larger than the other.
Healthy testicles are smooth, oval-shaped, and rather firm.
Most lumps are found on the side of a testicle, but they can also show up on the front, so check the whole testicle carefully. See your physician right away if you notice anything unusual. If the doctor confirms that something doesn't feel quite right, he or she may do an ultrasound examination, which uses sound waves to create an image of the testicles' interior. If the ultrasound shows an abnormality, your doctor may order blood tests that are helpful in diagnosing testicular cancer. This generally provides enough information to make a diagnosis.