What to do if i was just wondering how testicular cancer is caused, and what are signs of it?

Mass is common: Testicular cancer is usually detected by a mass or firmness in the testicle (scrotum). They can be quite small, but any abnormality in size or shape of the testicle should be evaluated. Ultrasound and blood tests for specific hormones (plap, hcg, alpha-fetoprotein, etc) can be used to detected if there is systemic disease.

Testicular mass: Usually painless. If this is not a cryptorchid testis and the person is not an intersex, it's basically dumb luck. There was a claim on an old retrospective study that physical fitness contributes to risk, but i believe this simply men exaggerating their achievements after losing a testis. Early puberty and lack of exercise are listed as possible risk factors.