Doctors might not do thyroid blood tests for Tourettes, but you can do tests privately DIY through the post easily.
If you do get thyroid bloods done at Doctors ask for a print out of the blood results and their ranges, (the ranges are important.)
Many illnesses are now linking with Thyroid, it might be a good idea to pop your results up on Thyroid UK,(on the website 'Health Unlocked') where members can see if there is a problem with the thyroid.
I have been reading this thread with a great deal of sympathy and interest. Googling Thyroid and Tourettes the first site that comes up is Tourettes
A startling statement is made right at the beginning of the paper that 20% of children experience some form of tics and tourettes.
The 3 papers quoted as reference (references 6-8) all refer to the same very small scale test in North Dakota.
I used to be a university moderator for research and ethics, and would have thrown out any paper which made such claims on the basis of such little evidence.
So please, when looking on the net, get a additional views from your doctor or health professional, before embarking on any DIY doctoring.
Apologies if I have seemed a little forward or have upset anyone, I only try to help, but I do know there is a connection.
On Wikipedia there is a reference to say that Hypothyroidism can be the cause of tics and mentions ruling Hypothyroidism out.
Not saying that it is what your Son has Scooby64.
There are good and clever Doctors out there, but many thyroid patients are being overlooked.
Some information here Scooby64:- (sorry I cannot seem to link it.)
I just wanted to caution people who are often desperate for any help they can find. That it looks scientific and authoratative doesn't make it necessarily so. Think back to the MMR scandal
Just a link you might be interested in reading Scooby64 about a nine year old Tourettes boy found to have thyroid - low T3, low within range T4 and a low vitamin D.