Overt hyperthyroidism and hypothyroidism are associated with inverted hemodynamic changes.Regional blood flow disturbances (including intrathyroidal) were also reported in these thyroid disorders. The purpose of this study is to investigate the thyroid vascularity and blood flow by Color Flow Doppler Sonography in patients with subclinical thyroid dysfunction

Color Flow Doppler Sonography (CFDS) has become in the last years an increasing procedure to assess the thyroid blood flow. Previous studies showed specific changes of thyroid blood flow in hyperthyroidism, Hashimoto's thyroiditis and thyroid nodules when investigated by CFDS. Subclinical hyperthyroidism and hypothyroidism are common laboratory findings, defined by normal thyroid hormones concentrations along with ,respectively,decreased or increase Thyroid stimulating hormone (TSH) level. We purpose to investigate thyroid vascularity by CFDS in patients with subclinical hyperthyroidism or hypothyroidism and compared them with euthyroid patients.

Inclusion Criteria:

• patients with subclinical hypothyroidism or hyperthyroidism
• patients with thyroid nodules and normal thyroid function

Exclusion Criteria:

• patients who are taking thyroxine, antithyroid drugs, lithium or amiodarone
• patients who had thyroid surgery or radioiodine therapy
• patients with NYHA class 3 or 4 heart failure

patients with subclinical hypothyroidism and hyperthyroidism