Hypoechoic nodules in the right lobe of the thyroid gland may be caused by simple nodular goiter, thyroid adenoma or thyroid cancer. 1. Nodular goiter: Hypoechoic nodules in the right lobe of the thyroid gland may be simple nodular goiter. (1) On plain ultrasonography, simple nodular goiter is characterized by a normal-sized or asymmetrically enlarged thyroid gland with an uneven surface and multiple or single nodules of varying echogenicity (hypoechoic, hyperechoic, or inhomogeneous echogenicity), with well-defined or blurred borders, and sometimes accompanied by varying degrees of calcification. (2) Doppler ultrasound shows thyroid nodules with varying blood supply, some with abundant blood flow, some with no or little blood flow. (2) Thyroid adenoma: generally, it is a solitary, homogeneous isoechoic nodule, and a few of them may be hypoechoic; the nodule is often round or oval, with clear borders and complete hyperechoic envelope. 3. Thyroid cancer: the cancer foci often appear as uneven, hypoechoic nodules with blurred borders and incomplete and unevenly thin and thick peripheral membranes; Doppler ultrasound shows that the blood flow in the nodules is abundant and chaotic, and some cancerous nodules may have peripheral partially encircling blood flow or no blood flow signals. Thyroid diseases are complex and varied, and when hyperechoic nodules are found in the right lobe of the thyroid gland, patients should promptly identify the cause of the disease and seek early treatment.