Sometimes when i jump and sometimes randomly i get cramps in my testicles. is that serious?

My take is: Your jumping-induced testicular cramps leads me to assume you're young and active. But just this tad of information is not enough to draw a conclusion. But clinically, such pain may result from brief twitch to a fine nerve fiber or muscle at action or jerking to twist testicles.To sort things out, need a more detailed analysis of the onset, degree, duration, evolution, and progress of the pain...