Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: (Almost) 4yo Boy, Many Symptoms, No AnswersBorn 3/2019.Waking up at night from a dead sleep with leg pain for nearly a year now. Happens once or twice a month usually. Right leg more frequently. Chalked up to growing pains. When he wakes up, give him Tylenol, get the heating pad out and wrap his legs. Rub his back and he falls asleep. Seems fine in the morning. Sometimes has complained of pain during the day, but could be a ploy for medicine. Points to his shins, knees, and thighs as sources of pain.Complains of headaches occasionally (I've never even heard the word, "headache" come out of his older brother's mouth). Goes away with Tylenol.Was vomiting a lot last year. I started tracking and the average was 1.5x a month. No fever or other symptoms; would complain of nausea, boot, then be back to normal within an hour. Went to pediatrician on 8/19/22, she recommended we go to the ER because we could get all testing done rapidly and at once. Went to ER, had bloodwork done (normal at the time, no cancer markers), was diagnosed with cyclical vomiting syndrome. Debated on whether to do a CAT scan or MRI, opted to not. Has only vomited 1x since then, was this past October. Not much nausea or vomiting since.Swollen lymph node in armpit and back of neck, both on left side. Just discovered armpit one today. Neck node has been enlarged for over six months. No biopsy, superficial exams by multiple doctors, all advise this is normal and not a concern. Soft, movable, and less than 2cm in size. Hasn't grown.He often just looks pale compared to the rest of the family (we are white, British decent), but could be chalked up to recent rainy weather and being stuck indoors for winter. He also seems thinner than the rest of us, just bonier than his older brother was. Always craves sweets. Weight and height are good, around 70th percentile.I found swelling in the back of his knee four weeks ago. Right posterior, left of the popliteal fossa, about the size of an avocado pit. Puffy, not hard. Took him to the pedi two weeks ago, and she said likely a cyst, but referred me to an orthopedic surgeon for further evaluation. Have appointment this Friday to get it checked (she said probably an ultrasound). She also checked him for a wet cough that he's had for over two months. Said she heard crackling in his lungs, prescribed inhaler, doesn't seem to be helping, will have a follow up next week to check his lungs again. Cough is annoying, but not really impacting day-to-day activities. Still very active and happy kid.Went on a long walk today and he woke up again with knee pain, said only right one hurts. Did the usual late-night treatment and now he's asleep.I am debating on whether to take him to the ER again. Our firstborn was healthy as a horse, never in the ER and sick with typical symptoms. I don't want to be too overzealous with an appointment coming up, but all of these symptoms just have my mom radar screaming there's something really wrong with him. I assume the ortho won't do another blood panel at the time, so it'll be a referral if they find something wrong. I just don't know if I want to keep dragging out discovery appointments for the next few weeks vs. going to the ER and asking for the gamut of tests.Any feedback at all is appreciated. We have a PPO and are financially stable, so cost isn't an issue.. ### Response: I've usually noticed that when your mom radar is screaming, it's better to take your kid to the ER. The symptoms you have mentioned could be due to a viral infection, but I'm still perplexed as to why the doctors decided against the CT or MRI and did they perform abdominal Ultrasound?. Also , cyclic vomiting syndrome can cause dehydration, lethargy , pallor, and muscle weakness. I hope he's taking his fluids well..