Health & Fitness

The thyroid may be small, but it’s critical to your child’s growth and brain development

3D rendering of the thyroid inside a person’s neck.
3D rendering of the thyroid inside a person’s neck.

The thyroid is a small but important gland.

Shaped like a butterfly, it’s located just below the Adam’s apple in the neck. The thyroid controls the body’s metabolism and maintains a general state of well-being, including how your child grows and how their brain develops.

The principal hormone produced by the thyroid gland is thyroxine, also called T4. Hypothyroidism occurs when the production of T4 is low. Children and adults with hypothyroidism may feel cold, have constipation, low energy and develop dry skin or hair. In females, menstruation can be heavy and prolonged.

Although children with hypothyroidism may be overweight, the thyroid hormone plays such an important role in maintaining growth, that obesity in children caused by hypothyroidism is almost always accompanied by slow growth.

Some babies are born with hypothyroidism, usually because the thyroid gland did not form normally. Babies born with hypothyroidism typically have no signs or symptoms in the first few months of life. However, if the hypothyroidism is not detected and treated early, severe problems with brain development occur.

That is why Florida and every state in the U.S. has a program to detect hypothyroidism as early as possible, allowing doctors to diagnose and treat congenital hypothyroidism within two weeks of birth.

Hypothyroidism can also occur in childhood and in adolescence. The most common condition in this age group is Hashimoto thyroiditis. In Hashimoto thyroiditis, the body produces proteins called antibodies that attack the thyroid gland. Some children are at greater risk for Hashimoto thyroiditis, such as those with Type 1 diabetes or Down syndrome.

Hypothyroidism can also develop as a side effect of certain medications. Some anticonvulsants and some psychiatric medications can cause a drop in thyroid hormone levels. The thyroid gland requires iodine to make the thyroid hormone, and as a result, iodine deficiency can cause hypothyroidism — although iodine deficiency is unusual in the U.S. because iodized salt is readily available.

Treatment for hypothyroidism requires replacing the thyroid hormone, usually by taking one pill of a thyroid hormone supplement a day. As thyroid hormone pills contain the same hormone that the thyroid gland produces, the body cannot tell the difference between the thyroid hormone in the pill and the hormone produced naturally.

In children and adolescents, once the proper dose of thyroid hormone replacement is determined, everything in the body that depends on the thyroid hormone should return to normal.

Although there is no real cure for congenital hypothyroidism or Hashimoto thyroiditis, children who receive appropriate treatment are expected to live a perfectly normal life. If you have concerns about your child’s health, share your concerns with your child’s primary care physician.

Dr. Tossaporn Seeherunvong is a pediatric endocrinologist with the University of Miami Health System. For more information, visit