Hypothyroidism is the decrease in the production of thyroid hormones which, depending on when it occurs, can affect a greater or lesser extent to the development of vital organs. Suffers a very small percentage of population and its causes can be congenital, environmental, extirpation of the thyroid gland or treatment with various drugs, such as iodine or lithium. For hypothyroidism in children, caused by congenital causes, is usually made to drink a clinical trial ( test the heel ). On the other hand, because during early gestation, mothers require an unusual effort on your thyroid gland, one of the risks encountered is hypothyroidism during pregnancy should be monitored especially for the successful development the fetus and the health of the mother. Idiopathic primary hypothyroidism occurs due to thyroid antibodies, or other cause autoimmune disorders ( autoimmune hypothyroidism ). Usually have symptoms of muscular fatigue, feeling of suffocation or pain in the thyroid area, hair loss, rough and dry skin and progressive deterioration of intellectual activity.