If you are relatively young.... doctors do this. They tend to do it for everyone,
but basically they form opinions about you within 10 secs. How you sit, how you present, your face eyes (may show puffiness etc), whether you fidget, all sorts of things.

Right now my son is going gluten free (he has tried it on and off) because he
feels strange, cold and numb when he eats gluten. He went to a GP in Sept and had testing, basic stuff, and all was normal. He was told to keep a food diary with symptoms's occurance for 2 months, and to return. It is difficult to be young and active socially and stay gluten free, so he has slips now and then.
The longer he follows the diet, the more obvious the symptoms when he slips.

I suggest you go to the Gluten forum here and read Megan's question, and also read the responses. She is beginning as well to investigate this.

If your GTT was only elevated one or 2 pts and you weigh alot, are very tall, etc or overweight, that is sometimes considered normal. If you were taking Risperdal when you had the test or just stopped it recently, your blood sugar can be off from that. Risperdal and other drugs of its type cause diabetes in some patients.

There may be ways for you to improve, that do not require a doctor at all.
But you have to tell us here some details about yourself in order for us to
suggest nutritional supports.