In the early diagnosis depends on the symmetry of the existence of soft and smooth goitre, may have low iodine intake or consumption of substances caused by a history of goiter, but this situation does not exist in North America. Thyroid radioactive iodine can absorb normal or high, accompanied by normal thyroid scan. thyroid test results are usually normal. late, can have nodules or cystic mass. Determination of thyroid antibodies should be excluded as a normal thyroid function in Hashimoto's thyroiditis causes goiter. endemic goitre, serum TSH can elevation, low serum T4 normal limit or slightly decreased, normal or mildly elevated serum T3.