Congenital Myxedema is a medical disorder that affects infants and young children. It is a condition that is characterized by a lack of thyroid hormone production, which leads to a slow metabolism and developmental delays. There are no direct antonyms for Congenital Myxedema, but the opposite condition to it is hyperthyroidism, which is an overactive thyroid gland. Hyperthyroidism causes symptoms such as weight loss, increased appetite, anxiety, and hyperactivity. It is treated with medication, surgery, or radioactive iodine. Congenital Myxedema, on the other hand, is treated with hormone replacement therapy, which involves taking synthetic thyroid hormones to restore normal thyroid function.