Because the thyroid controls so many body processes, including metabolism, heart rate, body temperature, etc, hypothyroidism does affect the whole body.
Following is a site that lists over 300 symptoms of a thyroid condition:
No, it’s really nothing to worry about. It does indicate that you have Hashimoto’s and the nodule will have to be watched to track whether it grows or not. It’s quite small, at this point, so they wouldn’t do anything with it, since it doesn’t have suspicious characteristics.
Since your ultrasound indicates Hashimoto’s, I’d have to wonder if you’ve had a thyroid blood panel (TSH, Free T4 and Free T3) and what those results (with reference ranges might be). I’d also wonder if you’ve had thyroid antibodies tested.
I’d also be interested in what prompted this ultrasound, since thyroid ultrasound is not a “routine” test. Do you have symptoms of a thyroid condition or been diagnosed with one? If so, please list your symptoms and tell us what condition you’ve been diagnosed with.