Thyroid nodule 4a is graded under thyroid ultrasound. Depending on the size and nature of the nodule, it needs to be treated with regular review, microwave ablation and open surgery. 1. Single focal nodule of ≤10mm, if it is not adjacent to the peritoneum, trachea, and laryngeal reentry nerve, follow-up observation is sufficient. 2. Multifocal nodules >10mm, or adjacent to the peritoneum, trachea, or laryngeal nerves, ultrasound-guided fine-needle aspiration pathologic examination can be considered. 3. For nodules >15mm, ultrasound-guided fine-needle aspiration pathology is recommended. 4. For nodules with compression symptoms, when biopsy confirms that they are benign, chemical ablation can be given if they are cystic nodules; if they are cystic solid nodules, surgery or thermal ablation can be given. 5. For nodules with malignant pathology, most thyroid cancers are preferred to be treated with surgery and a few types of radiotherapy. The nature of thyroid cancer is different, with different prognosis and surgical methods, and further examination is needed. It is recommended that patients with thyroid nodule 4a should go to regular hospitals in time to improve the relevant examination and standardize the diagnosis and treatment under the doctor’s guidance, so as to avoid delaying the condition.