The symptoms of thyroid cancer, the first point is the clinical manifestations of differentiated thyroid cancer. Most differentiated thyroid cancers are asymptomatic, with only occasional palpable nodules of varying sizes and textures, which can sometimes be detected in routine physical and imaging examinations. A few advanced thyroid cancers may produce noticeable symptoms due to large nodules or invasion of surrounding organs, such as compression of the trachea causing breathing difficulties, difficulty swallowing due to pressure on the esophagus, and hoarseness due to compression of the recurrent laryngeal nerve. The second point concerns the specific clinical manifestations of medullary thyroid carcinoma. The specific symptoms of medullary thyroid cancer include persistent watery diarrhea, not accompanied by severe malabsorption in the large intestine, often with facial flushing, some endocrine syndromes, and some associated conditions such as pheochromocytoma, multiple mucosal neuromas, and parathyroid adenomas.