Thyroid disorders in women.

Thyroid disorders include autoimmune thyroid diseases (AITD), thyroid goiter, nodule and cancer. AITD mainly consist of autoimmune thyroiditis and Graves disease. The common characteristic of thyroid disorders is female preponderance in their prevalence. The female-to-male rate ratio is reported at 4~6:1 for AITD and about 3~4:1 for thyroid nodule. For PTC, it is greatest during reproductive age and drops from five and more in patients aged 20-24, to 3.4 in patients aged 35-44 to one in patients over 80. The effects of female gonadal hormones and X chromosome inactivation on thyroid gland and immune system greatly contribute to the female predilection of AITD. The former mainly include prolactin and estrogen. The direct actions of estrogen on the thyroid tissue contribute to the development of thyroid goiter, nodule and cancer in women.