My dad just told me is testicles became huge all of a sudden? is it a hernia? is it something i need to call 911 for? he said it doesn't hurt. please

See you doctor: He needs to have an evaluation asap. If he develops pain, then go to er.

Probably a hydrocele: Not an emergency because not painful. Worth seeing a urologist and having a scrotal ultrasound. Low risk of being serious, but slight risk of underlying malignancy. Could be a hernia, but much more likely to be a hydrocele. Don't call 911!