Neck swelling 20 days after thyroid nodule surgery may be caused by local inflammation and edema reaction, local hematoma or emphysema, hypothyroidism, etc. According to the patient’s symptoms and general condition, we need to choose to continue to observe or to carry out surgery, medication and other treatments. 1. Local inflammation and edema reaction: thyroid surgery may cause a certain degree of tissue damage, so the local inflammation and edema reaction, usually within 2 months will gradually improve, it is recommended to continue to observe, if the patient has difficulty in breathing and other symptoms, timely surgical incision treatment. 2. Local hematoma or emphysema: due to postoperative bleeding or pneumoperitoneum, resulting in local hematoma or emphysema, resulting in neck swelling, which can be manifested as neck swelling 20 days after thyroid surgery. At this point, another surgery may be needed to open the incision and remove the hematoma or expel the gas. 3. Hypothyroidism: Since part of the thyroid gland is removed during thyroid surgery, hypothyroidism may occur. The patient shows weakness, drowsiness, etc. Swelling of the neck is seen. At this time, thyroid hormone, such as levothyroxine sodium tablets and other drugs need to be given for replacement therapy. The specifics of the medication should be followed by the doctor’s prescription. Thyroid nodule 20 days after surgery, found that the operation area swelling, you should promptly consult the doctor, improve the examination, clear diagnosis, and then follow the doctor’s advice!