To perform a self-examination of the testicles, move the penis out of the way before rolling the testicles one at a time between the thumb and forefinger to check for abnormalities, as instructed by the American Cancer Society. Feel for smooth, rounded bumps, hard lumps or any changes in shape and consistency.
Perform a self-exam when the scrotum is most relaxed, such as during or immediately after showering, as recommended by the American Cancer Society. Keep in mind that it's normal for one testicle to hang lower than the other or for one to be slightly larger. The testicles contain a small coiled tube on the outer side of the testicles, blood vessels and tubes that carry sperm, which may feel like abnormal lumps upon examination. Contact a doctor immediately if you have any concerns or notice any abnormalities.
If you have a family history of testicular cancer, an undescended testicle or a personal history of testicular cancer, consider completing a self-exam once per month, as instructed by the American Cancer Society. There are many reasons why one testicle may swell larger than the other, and non-cancerous conditions, such as hydroceles and varicoceles, may cause lumps. Only a qualified health care professional can make an accurate diagnosis.