There is no fasting requirement for the thyroid ultrasound, which means that you can eat before the thyroid ultrasound with no effect. Because the thyroid gland is an organ that has nothing to do with whether or not you eat during the examination, it is not like the examination of the gallbladder and other organs that have a direct relationship with eating. When checking the gallbladder after meals will cause the gallbladder to empty, for some diseases of the gallbladder can not be well detected, so do liver and gallbladder ultrasound requires fasting, simply do thyroid ultrasound does not have this requirement. However, it should be noted that if the thyroid ultrasound finds abnormalities, it is necessary to do thyroid function tests to match the diagnosis, and it is more accurate to draw blood for thyroid function tests on an empty stomach, so when doing thyroid ultrasound, the doctor will ask for an empty stomach in general, mainly as a precautionary measure, so that if there is a problem with the thyroid ultrasound, it is possible to do a one-time test on the blood, and then an accurate diagnosis can be made.