No matter what we do, we should be aware of the hazards, how many people do not understand the hazards of the disease, do not pay attention to the disease, miss the favorable treatment time, and finally threaten life and health, which is a vicious circle. Thyroid cyst belongs to a chronic disease, early symptoms are more insidious, easy to be ignored, as the cyst gradually increases, will cause a series of hazards such as a certain compression of the tissue around the thyroid gland, summarized as the following 4 major hazards. 1, thickening of the neck (due to cysts), the texture is generally soft, enlargement is obvious, the front of the neck mass can be protruding down or backward pressure caused by poor whistling, even whistling difficulties, or also cause swallowing choking sensation. 2, the enlargement to a certain extent will appear cervical lymph node metastasis; and can appear compression symptoms, such as poor inspiration, swallowing choking, hoarseness, and Horner’s sign (the diseased side of the pupil shrinkage, upper eyelid drooping, eye sunken, ipsilateral head and face no sweat, etc.). 3. If ischemic necrosis occurs in the tissue, a necrotic cyst will be formed. If the surrounding tissues are necrotic and the blood vessels lose tissue support and rupture, a hemorrhagic cyst will be formed. If plasmacytic, hemorrhagic and necrotizing cysts appear, the cyst wall is mostly fibrous connective tissue with less epithelial cells. 4. Cysts formed by degenerative nodules may be cystic in the whole nodule or partially cystic, thus forming partially solid and partially cystic masses; thyroid carcinoma may form cysts due to necrosis, bleeding and liquefaction, and thyroid cysts may also become cancerous.