What Causes Snoring And Difficult Breathing In A Child?

My older son was diagnosed with mono. I believe my younger son (almost 3 yo) now has it, although I haven t taken him to the doctor. (symptoms started 5 days ago). As of last night, he has started snoring loudly and seems to have a lot of difficulty breathing through his nose, especially when sleeping. At times he seems to stop breathing for a couple of seconds. Because of this, he s having great difficulty sleeping and is quite uncomfortable. I m assuming this is due to swollen tonsils/adenoids. Since he sounded better during the day, I didn t take him to doctor, but during his nap he was having the same problems. Will he be okay throught he night or should I try to get him to see a doctor this evening? Thank you!