Hypothyroidism, or hypothyroidism, is a very common endocrine disorder that affects newborns with physical and intellectual developmental disorders, so it should be given some attention. Most hypothyroid children are born without symptoms, and the early appearance and severity of these symptoms are related to the intensity and duration of the disease. Newborns with hypothyroidism have a dull expression, little movement, low and little crying, difficulty suckling, often in a sleepy state, and low response to the outside world. Some newborns show a large head circumference, a marked widening of fontanelle, delayed defecation, constipation, feeding difficulties, easy vomiting and choking, abdominal distention, umbilical hernia, and a temperature that does not rise. In terms of skin, the skin is cool and wet, there are spots and wrinkles on the forehead, and the tongue is large and thick and often sticks out of the mouth, which can lead to breathing difficulties in severe cases. Neurologically, the child’s expression is dull, his neurological reflexes are slow, and his motor development is delayed, such as turning over and sitting up. On auscultation, a slow heart rate and low heart sounds may be observed. In daily life, parents should pay close attention to the development of their newborns and take their children to the hospital for regular follow-up examinations to check the level of development of their bodies to avoid stunting.