Thyroid cystic nodule 0.8 cm is usually not serious, but it still needs to be analyzed in the context of specific conditions, and it is recommended to consult a doctor. In color ultrasound examination of the thyroid gland, thyroid nodules are classified into 6 grades, and the higher the grade, the higher the risk of thyroid cancer. Thyroid nodules graded at grade 3 or below have a higher probability of being benign nodules, while grade 4 or above may be malignant, and grade 6 can be determined to be malignant. Cystic thyroid nodules are generally a sign of benignity, and if there are no obvious symptoms, they can be reviewed regularly under the guidance of a doctor. If cystic thyroid nodules grow rapidly and are accompanied by calcification and unclear boundaries of the nodules, puncture examination of cystic thyroid nodules is needed to determine whether they are malignant and active treatment is recommended by the doctor.