most common causes of hypothyroidism in the adult are Hashimoto's disease, in which the immune system makes antibodies against the thyroid, and the over treatment of hyperthyroidism by radioactive iodine or surgery. Hypothyroidism in newborns is caused by a congenital defect in which the baby is born with no thyroid or one that does not produce enough hormone (Holub & Jacob, 1995). Detecting congenital hypothyroidism is particularly important because without adequate levels of thyroid hormone, the brain does not develop properly and this causes mental retardation and growth problems. Irreversible brain damage can occur by the age of three months if the condition is not treated (Everything You Need to Know, 1996). Babies with this condition will be lethargic and fail to thrive. Undiagnosed congenital hypothyroidism can cause cretinism, which is characterized by jaundice, poor appetite, constipation, a hoarse cry, outpouching of the naval and slow bone growth. Hypothyroidism is characterized by a slowing down of all body processes. The first symptoms are barely noticeable, and include feelings of lethargy, aching muscles, intolerance to cold, constipation, and weight gain, even with a reduced food intake. The face becomes puffy and the skin dry; the voice deepens and depression may ensue. Early detection can prevent the development of most, if not all, problems caused by thyroid hormone deficiency.
Hypothyroidism is diagnosed by screening for hormone levels in the blood. Congenital hypothyroidism is characterized by low or absent levels of thyroxine at birth. It affect approximately one in 5,000 newborns. Girls are affected three times more often than boys. Hypothyroidism produces few signs in newborns, so it often goes undetected and cretinism sets in, or the infant dies of respiratory distress (Everything You Need to Know, 1996).
The test for hypothyroidism in newborns should be done before the infant is dis...