If my newborn has a lump in his scrotum, does he have a hernia?

Maybe. A lump in your baby's scrotum could be related to a hernia, which is a piece of the intestine that finds it way to the scrotal sac. Or the swelling in the scrotum could be a hydrocele, an accumulation of fluid in the scrotum. Or it could signal trauma to the area, or a torsion, which happens when the testicle twists upon itself, which can be serious. Ask your doctor to check your baby's scrotum.
Possibly. There are a few possibilities, including a hernia, and your son needs to be examined right away to determine the cause. Some other causes include hydrocele, which is excess fluid in the scrotum, and torsion, which is a twisting of the testicle.
Hydrocele or hernia. More likely hydrocele. Hernia should be reducible with a squishy feeling as bowel is pushed back into abdomen. An incarcerated hernia should be painful + red skin discoloration. Hydrocele just contains fluid and is not easily reducible. Newborn or perinatal testis torsion is a hard, bluish lump if longstanding or red and tender if recent. If in doubt get an ultrasound. Occasionally is testis tumor.
Maybe. Could be a hernia or hydrocele, which is a collection of fluid only. A testicular mass is also possible, but way less likely. See you pediatrician or a pediatric surgeon for an exam to find out.