The scar is getting bigger and bigger two months after thyroid surgery, which may be due to the patient’s keloid, scar hyperplasia and postoperative infection. 1. Keloid: The cause of keloid is still unclear, and is usually thought to be related to genetic factors. Patients with keloid scarring will also form obvious scars after minor trauma, and the increasing size of the scar two months after thyroid surgery may be due to this type of constitution. 2. Keloid hyperplasia: keloid hyperplasia is a result of excessive repair of the body’s fibrous tissues after the patient has been traumatized, and irregular swellings or smooth strips will appear in the affected area, accompanied by pain, itching and other symptoms. 3. Postoperative infection: improper postoperative care may cause bacterial infection, resulting in inflammation, due to the stimulation of inflammation will lead to the growth of granulosa cells become denser, resulting in larger scars. Adverse reactions to the incision after thyroid surgery should be examined and treated by a doctor.