The thyroid gland is located in the anterior cervical region, and when the thyroid gland is diseased, it may appear as a “thick neck”, which is called a “big neck”. However, “big neck” cannot be equated with hyperthyroidism, because only some patients with hyperthyroidism have “big neck”, not all. In addition, patients with hypothyroidism, goiter and goitre can all have “big neck”. Therefore, if you find your “thick neck”, you should go to the hospital in time to have further examination by a professional doctor to identify different cases, instead of simply thinking that “big neck” is hyperthyroidism.