Thyroid nodules are not contagious. Thyroid nodules are not contagious. Thyroid nodules are lumps in the thyroid gland that move up and down with the thyroid gland in response to swallowing motions, and can be caused by a variety of factors. They are usually detected by thyroid ultrasound or physical examination. There are benign and malignant thyroid nodules. Benign thyroid nodules include multinodular goiter, Hashimoto’s thyroiditis, cysts, follicular adenomas, and Hürthle cell adenomas. The vast majority of malignant nodules are thyroid carcinomas, and a few are primary thyroid lymphomas or metastatic thyroid carcinomas (breast cancer, renal cancer, etc.). Infectious diseases are diseases that are caused by direct invasion of the body by pathogens such as bacteria, viruses, parasites, spirochetes, mycoplasmas, etc. and can be prevalent in the population. Thyroid nodules, on the other hand, are usually associated with heredity, environment, diet and thyroid-related hormone disorders. In conclusion, thyroid nodules are not contagious and thyroid nodules should be diagnosed and treated under the guidance of a physician.