Whether a grade 4 thyroid nodule is serious or not needs to be considered in the context of the nature, size and location of the nodule. If the nodule is malignant, it is usually more serious and prompt medical attention is recommended. If the nodule is benign and has no other symptoms, it is usually not serious. There is no authoritative data on how many years you can live with grade IV thyroid nodules, so it is recommended that you seek medical attention promptly. Thyroid nodule TRAB grade 4 is a possibly malignant nodule, which is categorized into 4a, 4b and 4c, with 4a having a malignant risk of 2% to 10%, 4b having a malignant risk of 10% to 50%, and 4c having a malignant risk of 50 to 90%. If the rating is 4, fine needle aspiration biopsy is recommended to determine the benign or malignant nature of the nodule if there is a possibility of malignancy. In general, most thyroid nodules are benign and do not require special treatment, regular review is sufficient; even if the thyroid nodules are malignant, the current cure rate of thyroid cancer is very high, as long as timely treatment and no metastasis, basically does not affect the life expectancy. Thyroid nodules should be detected, diagnosed and treated early, and most of them can achieve very good results, and it is recommended to consult your doctor for specific treatment plan.