Because you'd be stupid not to! Although testicular cancer is rare in teenagers, overall it is the most common testicular cancer in males between the ages of 15 and 35! The good news is that it is almost always curable if it caught & treated early.
It's important to try to do a TSE every month so you can become familiar with the normal size and shape of the testicles, making it easier to tell if there are any unusual lumps or bumps, which can be the first warning signs.
How to do it
It's best to do a TSE during or right after a hot shower or bath. The skin that covers the testicles is most relaxed then, which makes it easier to examine the testicles.
Examine one at a time. Use both hands to gently roll each (with slight pressure) between your fingers.
Place your thumbs over the top of your testicle, with the index and middle fingers of each hand behind the testicle, and then roll it between your fingers.
You should be able to feel the epididymis (the sperm-carrying tube), which feels soft, rope-like, and slightly tender to pressure, and is located at the top of the back part of each testicle. This is a normal lump.
Remember that one testicle (usually the right one) is slightly larger than the other for most guys - this is also normal.
When examining each one, feel for any lumps or bumps along the front or sides. Lumps may be as small as a piece of rice or a pea.
If you notice any swelling, lumps, or changes in the size or colour of a testicle, or if you have any pain or achy areas in your groin, let your doctor know right away. Lumps or swelling do NOT automatically mean cancer, so don't freak out. But only your doctor can decide by using further more specialized tests.