My oldest son (who has a twin brother) has a lump in his chest. We took him to the doctor who ordered an ultrasound of the lump. Turns out that the lump is gynecomastia and should go away in about a year. But while they were doing the ultrasound, they found larger lymph nodes in his armpits. He did a physical and found more in his groin. The doctor asked a bunch of questions about weight loss and tiredness and said it could possibly be mono but he doesn’t have any other symptoms for that. My husband and I had Mono when we were in our 20’s for almost a month - and we could barley function at university/work. We’d come home and immediately fall asleep until the next morning, missing meals etc. Our son is tired- but he’s a teenager and is definitely not sleeping more than usual. The doctor then asked a lot about if my moms cancer was in her lymph nodes. (My Mom passed away of Cancer when I was 30 and we are all still mourning the devastating loss) The doctor then said he needs blood work to rule that among other potential things, out. We go for blood work today (as the labs were closed by the time we finished the appointment yesterday). If we hadn’t noticed the lump, we would have not gotten the ultrasound. If the Tech didn’t look all the way up into his underarms, we wouldn’t have known about his enlarged lymph nodes, and our family doctor wouldn’t have palpated other areas to see that those lymph nodes were enlarged too. We are on pins and needles - and I’m wondering, how did you find out your child had a serious illness?