Why is goiter not as rare in the united states?

Not true. Good old fashioned iodide deficient goiters are no longer seen in the US. However, when imaging studies are done for other reasons, we are beginning to ascertain incidentally generous sized thyroid glands (and nodules within the gland) more often. If the function of the gland is normal, and there are no antibodies against the gland in a person without any compressive symptoms, this can be ignored.