Diffuse thyroid lesions are not scary, and are mostly caused by Hashimoto’s thyroiditis resulting in an enlarged thyroid gland on ultrasonography suggestive of diffuse thyroid lesions. Common causes of thyroid lesions (goiter) are: 1) non-inflammatory: such as endemic goiter, nodular goiter, toxic diffuse goiter, etc.; 2) inflammatory: such as Hashimoto’s thyroiditis (chronic lymphocytic goiter), subacute goiter; 3) the thyroid gland can also be enlarged due to a thyroid tumor. In most cases, goiter is an enlargement of the thyroid gland that is not due solely to a tumor. Therefore, lesions caused by various etiologies occur throughout the thyroid gland, so ultrasound will often indicate diffuse thyroid pathology. Diffuse thyroid lesions do not mean malignant lesions, and diffuse thyroid lesions are not clearly related to malignancy. In conclusion, if diffuse thyroid lesions are present a thorough evaluation is needed to identify the cause of the enlarged thyroid gland and to provide timely intervention.