Best test: TSH. Thyroid stimulating hormone (TSH) is usually the first test in a patient who has symptoms suggesting hypothyroidism. It will identify most types of hypothyroidism. Follow up tests may include free t4, and sometimes thyroid antibodies such anti -microsomal ab if the results are borderline. Be aware that the TSH is high when the thyroid level is low. Look at http://www. Amarillomed. Com/howto/#thyroid.