The test is to see if you have Hashimoto's. And it seems more as if the answer is yes or no. If you are below the range the answer is No. If you exceed the upper limit then the answer is probably yes. Some tests come back barely at the top. Yours however is pretty diffinitive.
The fact that the number is so high is nothing to worry about. What it would indicate is that your immune system is actively and significantly attacking your thyroid gland. So your thyroid will start to become less and less effective in its ability to produce thyroid hormone.
Again don't get too alarmed. All it means that sooner or later you will need to begin adding thyroid hormone by medication to make up for what your thyroid gland is no longer able to do. As Barb135 stated above. It is the most common cause for being Low Thyroid ("Hypo").
What symptoms do you have (if any)? I suspect you must have had some symptoms that caused your Dr ot order the test.
Do you have any other blood lab results? If so please post them along with the reference ranges.
Did you wind up having cancer? Mine is 150 and dr is also concerned.
It probably means you have Hashimoto's thyroiditis, although this is just an educated guess at this point. That's what I've got and my TGab is ">3000". You know your in trouble when they stop counting and just throw in the ">"! It's an indication of the speed at which your thyroid is being attacked by the antibodoes. Don't panic. Hashi's is the most common cause of hypothyroidiism in the States.
Do you have TSH, free T3 and free T4 to post along with their ranges?
I am waiting for my doc to call and I am so scared. All my results are normal but this is really is scaring me
What did your doctor say about this high number? I don't think it is good. When mine was above 200 before my thyroidectomy the doctor strongly felt that I had cancer. Im not sure if thyroglobulin and thyroglobulin AB is the same. I would ask your doctor what the high number could mean!
Good luck!