Most cases of “thick neck disease” are caused by thyroid disease. The thyroid gland is located in the front of the neck and is invisible to normal people. Once the thyroid gland is diseased, sometimes the enlarged thyroid gland can be seen, especially when eating or drinking. The enlarged thyroid gland can be divided into three degrees: one degree of enlargement is invisible but palpable; the second degree of enlargement is visible and palpable, but its size does not exceed the anterior border of the sternocleidomastoid muscle; and the third degree of enlargement is when the enlarged thyroid gland exceeds the anterior border of the sternocleidomastoid muscle. The common clinical thyroid disorders include hyperthyroidism, endemic goiter, nodular goiter, Hashimoto’s disease (chronic lymphocytic thyroiditis), thyroid adenoma, thyroid cyst (single or multiple), and thyroid cancer. Therefore, when you find a thick neck, don’t ignore it and make sure to visit a general hospital with certain conditions, especially a hospital with a thyroid specialist. The doctor can initially determine what causes the thick neck based on your onset and clinical presentation, and then give you some corresponding tests. You may also have medical imaging tests such as thyroid ultrasound, isotope scan (ECT), CT, PET, etc. If necessary, a pathological examination, called thyroid smear cytology, will be done to make a diagnosis and then treat the symptoms. We would like to advise people suffering from thyroid disease to go to a hospital with a thyroid specialist to receive treatment. In the process of your visit, you will learn some general knowledge about this disease, have a better understanding of your condition, be informed, not blind, spend less money, diagnose early, treat early and recover early.