Diffuse thyroid lesions are a group of diseases that occur in the thyroid gland, so named because the lesions are often diffusely distributed. These include Hashimoto’s thyroiditis, nodular goiter, subacute thyroiditis, toxic diffuse goiter, and thyroid cancer. Different diseases are treated differently and have different prognoses, so it is impossible to generalize whether they are treatable or not. However, regardless of the presence of any disease, active cooperation with treatment is beneficial to the treatment, recovery and prognosis of the disease. Hashimoto’s thyroiditis is a common thyroid disease, and in cases where the thyroid gland is functioning normally, patients can generally be treated without special treatment and can be observed regularly. And if the corresponding symptoms appear, they can also gradually recover after taking systematic and comprehensive medication. In the case of subacute thyroiditis and toxic diffuse goiter, although most patients have a relatively good prognosis after active cooperation with treatment, there is a possibility of recurrence, so regular review is recommended. However, diffuse thyroid lesions such as nodular goiter and Hashimoto’s thyroiditis have a certain chance of becoming cancerous and require lifelong thyroid hormone replacement therapy after the indication of malignancy and surgical stage removal. In the case of diagnosed thyroid cancer, the same lifelong treatment is required. At this time, the condition is relatively serious and patients are advised to actively treat it in order to improve their quality of life.