Understanding the Thyroid

As pediatricians, parents often ask us about the thyroid and how it may be affecting their children. Could it be responsible for fatigue? Weight gain or weight loss? Mood changes? While these symptoms could be due to other health issues, the thyroid could be the cause. To gain a better understanding, let’s take a look at what the thyroid is responsible for and what can happen if it is not functioning properly.

What is the thyroid?

A butterfly-shaped organ in the middle of the neck, the thyroid is a gland responsible for producing a number of hormones (thyroid hormones) that are released into the bloodstream and circulate throughout the body. Its function is controlled by the pituitary gland, located in the brain.

Thyroid hormones act on every cell in the body to help regulate metabolism, growth and development, and body temperature. Normal levels of thyroid hormone are especially essential during infancy and early childhood for normal brain development, which is why thyroid function is part of newborn screening tests.

What happens when the thyroid isn’t working properly?

There are a few conditions that may occur if the thyroid isn’t functioning properly:

  • Hypothyroidism: The thyroid gland doesn't produce enough of the active hormone
  • Hyperthyroidism: The thyroid over-produces the active hormone
  • The thyroid can also become diffusely enlarged (goiter) or develop growths (nodules)

These conditions may or may not cause medical issues, so it’s important to be evaluated by a medical provider.

Could it be hypothyroidism?

Hypothyroidism is very common, occurring in about 1 in 1,250 children. It can be present at birth (congenital hypothyroidism), or develop later in childhood or adulthood (acquired hypothyroidism).

Unfortunately, the symptoms of hypothyroidism are non-specific, can develop slowly over time, and overlap with those of other conditions. They include:

  • Tiredness
  • Modest weight gain
  • Feeling cold
  • Dry skin
  • Hair loss
  • Constipation
  • Developmental delays or school issues
  • Poor growth, especially slowing of height
  • Delay of puberty

Hypothyroidism can result from problems with either the thyroid or pituitary gland. These problems include a deficiency present at birth, damage from an immune system antibody attack (autoimmune), injury/surgery, or exposure to certain medications, radiation and substances. The most common cause in children and teens is an autoimmune process affecting the thyroid gland.

Could it be hyperthyroidism?

Hyperthyroidism is much less common in children than in adults and significantly rarer in this age group than hypothyroidism. Similarly, it can be present at birth (congenital) or develop as a child ages (acquired).

The symptoms of hyperthyroidism can also overlap those of other medical conditions and develop over time. They include:

  • Nervousness or irritability
  • Trouble concentrating or school performance issues
  • Poor weight gain or weight loss
  • Heart racing/beating fast
  • Feeling hot or sweating more
  • Hand tremor
  • Difficulty sleeping
  • Wide-eyed stare/Eyes bulging
  • Feeling a “lump” in the throat

Mirroring hypothyroidism, hyperthyroidism can result from the same causes affecting either the thyroid or pituitary gland. The most common cause is also the same – an autoimmune attack on the thyroid gland itself.

How do I know if there is a problem and what are the treatments?

If you feel as though your child or teen may be experiencing a thyroid issue, speak with your pediatrician. A complete history and physical exam, along with a simple blood test, are the first steps to finding the answer. If a thyroid problem is diagnosed, an endocrinologist will be consulted. There are many safe and effective treatments, such as hormone replacement, which can be directed by your medical team and will control the symptoms.