Be alert if:
you find a small, hard, painless lump on the front or side of the testicle.
one testicles decreases in size significantly.
your scrotum feels heavy or there is a sudden collection of fluid
you have a dull ache in the lower abdomen or the groin.

Don’t panic if you feel free floating lumps, not attached to anything; if you have a spot on the scrotal skin or if you have blood in your semen. These are not sighs of cancer, although you may have it checked out.