Your thyroid is a butterfly-shaped gland that is located in the neck. It makes 2 hormones, T3 & T4.
The thyroid hormones are made by the thyroid gland in response to another hormone called Thyroid Stimulating Hormone (TSH). TSH is made by our main hormone control center, the pituitary gland, which is located in the brain.
Why is the Thyroid Gland important?
Thyroid hormones (T3 & T4) help control our metabolism, digestion, and regulate our temperature. Thyroid hormones are also very important to early brain development (up to age 3) and normal growth throughout childhood.
How do we test thyroid function?
Examining how well the thyroid gland is working requires a blood test. The most accurate evaluation includes TSH and free (active) T4 levels.
Normal ranges for TSH and free T4 can vary based on age, lab, weight, recent illness, and individual differences. Below are typical normal ranges for TSH and free T4.
3 Common Thyroid Problems in Children
#1 – Congenital Hypothyroidism
Congenital means that someone is born with a medical problem.
In this case, either a person is born without a thyroid gland, or their thyroid gland does not make enough hormones. Congenital hypothyroidism can cause mental retardation and growth problems if not recognized quickly. Because of this, we screen all newborns for congenital hypothyroidism with a Newborn Screen (formerly called a PKU).
As long as someone with congenital hypothyroidism gets medication to replace their thyroid hormone, the will grow and develop normally.
Sometimes congenital hypothyroidism can be temporary, but most individuals require lifelong medication.
#2 – Hypothyroidism
Hypothyroidism = underactive thyroid.
Thyroid hormone (free T4) levels are low because the gland is not making enough. TSH is usually high, trying to force the thyroid gland to make more hormones.
Autoimmune hypothyroidism, sometimes called Hashimoto’s, is the most common cause of hypothyroidism. The immune system attacks the thyroid gland, causing inflammation and decreased hormone production.
Hypothyroidism can be more common in people with other autoimmune disorders (Type 1 diabetes, celiac disease, etc.).
It is also more common in certain genetic disorders, including Trisomy 21 (Down Syndrome), Turner Syndrome, & Prader-Willi Syndrome.
#3 – Hyperthyroidism
Hyperthyroidism = overactive thyroid.
Thyroid hormone (free T4 & T3) levels are high because the gland is making too much hormone. TSH is low, trying to stop the thyroid gland from making from making more hormones it doesn’t need.
Hyperthyroidism can occur if the there is one spot or nodule in the gland that is making too much hormone (sometimes called a “hot nodule”). Hyperthyroidism can also occur due to an autoimmune attack on the thyroid gland. This may be referred to as Grave’s disease.
Untreated hyperthyroidism can be life threatening because it causes your blood pressure & heart rate to rise.
Side by Side Comparison of Hypothyroidism & Hyperthyroidism
About Hillary Lockemer, MD
Dr. Hillary Lockemer is a pediatric endocrinologist with WakeMed Physician Practices – Pediatric Endocrinology. She is board certified in pediatrics and pediatric endocrinology and has been involved in numerous research studies related to pediatric endocrinology.