How serious could swollen lymph nodes be?
Many things can cause the nodes to swell and do their work against infection and many other unhealthy things. How serious? Could be as bad as some cancer. Unlikely due to age of your boy, but possible. I will say a prayer for your son and that you will quickly have a diagnosis and can receive the needed treatment to help his body get well. He sounds like he doesnt have any other symptoms so take heart in that and also in the knowlege that kids have a wonderful ability to get well. Dont panic him with your feelings. Calm yourself and take a step at a time. If you really think you are going out of your mind, see a therapist/counselor/pastor to get some emotional support.