What Tests Are Done To Detect If Someone Has Diabetes Before That Person Starts Showing Symptoms Of It?

What tests are done to detect if someone has diabetes before that person starts showing symptoms of it?

Is There Anyway For Your Doctor To Detect Diabetes At A Physical Without Knowing?

If someone were to go get a normal routine physical at the doctors would he without checking for it, come across diabetes, if he didnt take urine? Just wondering. Thanks!