The term “thyroid grade 5” generally refers to “thyroid nodule category 5”, which is the ultrasound classification of thyroid nodules, and is highly suggestive of malignancy, with a >90% malignancy rate, and therefore may be more serious. Patients found to have thyroid nodule category 5 are recommended to be punctured if the nodule is >10mm; puncture may be considered at >5mm if the nodule is adjacent to the peritoneum, trachea, or laryngeal reentrant nerve or if the nodule is multifocal. If there is a tendency to malignancy or a significant increase in volume after evaluation by a specialized physician, surgery is generally required; if the nodule is benign and asymptomatic, regular review is generally sufficient. In conclusion, patients with thyroid nodules of category 5 are advised to consult a medical professional for diagnosis and treatment.