Clinically, diseases such as Hashimoto’s thyroiditis, nodular goiter, thyroid cancer, and Graves’ disease can manifest as diffuse thyroid lesions. For example, Hashimoto’s thyroiditis, also known as chronic lymphocytic thyroiditis, is an autoimmune disease, most often seen in young and middle-aged women, with a normal or slightly enlarged thyroid gland in the early stages and diffuse enlargement in the late stages, often without specific symptoms. Nodular goiter is an enlargement and hyperplasia of the thyroid gland caused by iodine deficiency. The thyroid gland may revert after iodine supplementation, and multiple hyperplastic nodules may form due to repeated iodine deficiency and repeated reversion. The common pathological types of thyroid cancer are papillary carcinoma, follicular carcinoma, medullary carcinoma, etc. The morphology of the masses is mostly irregular with infiltrative growth. When a diffuse thyroid lesion is found clinically, there is no need to panic. You should visit a regular hospital in time to improve thyroid function, thyroid MRI and other tests to clarify the cause and proceed to the next step of treatment as early as possible.