Hypothyroidism

There are two types of hypothyroidism that affect children:

• Congenital hypothyroidism. Congenital hypothyroidism is present at birth. This condition is not hereditary. There are many reasons why this condition may develop. They are:
  • The thyroid gland does not develop properly in utero (it is missing, too small or located in the wrong place).
  • The thyroid gland develops properly but does not produce enough hormones.
  • The thyroid gland develops properly but does not receive the right signals from the pituitary gland (the gland located at the base of the brain that controls the thyroid gland).
  • The thyroid gland develops properly but is suppressed by medicines the mother takes while pregnant (typically to treat hyperthyroidism). This cause of congenital hypothyroidism may be temporary.

If left untreated, congenital hypothyroidism can cause an intellectual disability or delayed growth. Because the condition often shows no symptoms during the first week of life, all U.S. hospitals screen newborns for the condition before they go home.

• Acquired hypothyroidism. Acquired hypothyroidism can develop at any age. The most common cause of acquired hypothyroidism in children and teenagers is a direct attack on the thyroid gland by the immune system (called Hashimoto thyroiditis). Other causes include:
  • Damage to the thyroid gland by radiation therapy for cancer
  • Damage to the thyroid gland after surgery for thyroid cancer, hyperthyroidism or a goiter
  • Damage to the pituitary gland by a severe brain injury or radiation therapy for cancer
  • Too much or too little iodine in the diet
  • Medicines that interfere with thyroid hormone production such as lithium and some cancer and infection fighting medicines

Children and teenagers with some other disorders are at a greater risk for acquired hypothyroidism—especially those with Down syndrome and Type 1 diabetes.

Symptoms of congenital hypothyroidism may include:

• Weak cry
• Feeding problems
• Sleeping significantly more hours than the average infant
• Constipation
• Jaundice (yellowing of the skin and whites of the eyes)
• Poor muscle strength
• Puffy face
• Large tongue
• Swollen stomach
• Fontanelles (soft spots) that are abnormally large

Symptoms of both congenital and acquired hypothyroidism may include:

• Extreme fatigue
• Feeling cold
• Dry skin
• Hair loss
• Modest weight gain (5-10 pounds)
• Constipation
• Failure to thrive

Diagnosis of Hypothyroidism

Your child's doctor at Riley at IU Health can use the following exams or tests to diagnose hypothyroidism:

• Physical exam. Your child's doctor can feel the thyroid by physically examining the neck. An enlarged thyroid gland may indicate a thyroid problem.
• Blood tests. A blood test can check the level of hormones produced by the thyroid and pituitary glands. Low levels of hormones produced by the thyroid indicate hypothyroidism.
• Imaging scan. The doctor may order an imaging scan to see if the thyroid gland is missing or too small.