Whether diffuse changes in the thyroid parenchyma are serious or not depends on the specific circumstances of the thyroid lesion for objective analysis. First, if the thyroid parenchyma is accompanied by multiple nodules, the diffuse nodules are considered as malignant tumors by ultrasound examination, which are often accompanied by extensive invasion of the surrounding lymph nodes. Surgery is needed to remove the thyroid gland and clear the surrounding lymph nodes as soon as possible. After surgery, iodine-131 radiotherapy can be combined to kill the cancer cells in the body as much as possible to prolong the patient’s life. Secondly, if the patient has diffuse hyperplasia of thyroid gland due to disorder of thyroid hormone level, most patients can maintain the thyroid hormone within normal level through medication to reduce the diffuse change of thyroid gland, and the patient’s condition is not serious, so surgery is not necessary and the prognosis is relatively good.