When I read this thread again, I noticed that I left out the link to hypo symptoms. Here it is.
http://endocrine-system.emedtv.com/hypothyroidism/hypothyroidism-symptoms-and-signs.html
Might be worth going through with your son and marking which ones he seems to have, and then taking a copy with you to show the doctor.
thanks for you advise and I will contact his doctor right away.
If you look at the list of 26 typical hypothyroid symptoms in this link, how many does your son have? If he is already having hypo symptoms, I would not wait two months. I would go back and request testing for Free T3 and Free T4 and if the doctor resists or makes excuses as to why it is not necessary, just insist on it and don't take no for an answer. If the Free T3 is in the lower half of the range, that is frequently associated with being hypo. Also, if your son has never been tested for the thyroid antibodies, TPO ab and TG ab, that should be done as well, to find out if Hashimoto's Thyroiditis is involved.
So if your son is having symptoms, and has a Free T3 in the lower part of the reference range, then you should request that he be started on thyroid meds. A good thyroid doctor will treat a hypo patient clinically by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels. Symptom relief should be al important, not just test results. Many of our members report that symptom relief for them required that Free T3 was adjusted into the upper part of its range and free T4 adjusted to around the midpoint of its range.
I think you will get some good insight from this link to a letter written by a good thyroid doctor for patients that he consults with from a distance. The letter is sent to the PCP of the patient to help guide treatment.
http://hormonerestoration.com/files/ThyroidPMD.pdf