Thyroid cancer blood test may have abnormalities in the blood tumor markers of thyroid cancer, such as calcitonin, carcinoembryonic antigen, thyroglobulin, etc. Definitive diagnosis needs to be combined with other tests. Thyroglobulin is a specific protein produced by the thyroid gland, but it lacks specificity for the definitive diagnosis of thyroid disease. Generally, thyroglobulin is seldom used as a preoperative diagnostic criterion for differentiated thyroid, but after surgery, thyroglobulin can play a certain role in suggesting tumor recurrence. Calcitonin as well as carcinoembryonic antigen are suggestive of thyroid cancer. Medullary carcinoma is considered in patients with high levels of calcitonin, and carcinoembryonic antigen above normal is also suggestive of medullary carcinoma. Abnormal items in blood test of thyroid cancer have a certain suggestive function, and it is necessary to improve other tests to make a clear diagnosis, and it is necessary to consult a doctor in time for abnormal blood test, and do not make judgment on your own, which may delay the time of treatment.