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Thyroid Conditions

The thyroid gland is a butterfly-shaped organ located in the front of the neck and plays an important role in the body. It produces hormones that control brain development and growth and regulates metabolism.

The most common thyroid problems are hypothyroidism, hyperthyroidism and thyroid nodules, which are all treatable.


Hypothyroidism means the thyroid gland is under-reactive or produces too little thyroid hormone. The most common cause is an autoimmune disorder known as Hashimoto’s thyroiditis, which usually runs in the family and there is nothing that can be done to prevent it.

There are two main types of hypothyroidism. The first is congenital hypothyroidism, which is often diagnosed during mandatory newborn screening tests. One in 2000 - 4,000 babies are born with the disease.

The second is acquired hypothyroidism, which usually appears in adolescence but can happen at any age. One in 2,000 children are diagnosed with the disorder. Hashimoto’s thyroiditis is the most common cause of acquired hypothyroidism.

Symptoms and diagnosis

Babies with hypothyroidism will usually not have any symptoms since it is diagnosed soon after birth with the newborn screening. Older children may experience growth failure, modest weight gain, fatigue, tiredness, constipation, cold intolerance, dry hair and menstrual irregularity. Your child's health care provider can typically see and feel an enlarged thyroid gland. A simple blood test can determine if your child has hypothyroidism.

It is important to note that while hypothyroidism can cause weight gain, weight gain is very rarely caused by hypothyroidism. We know obesity and weight gain can cause mildly abnormal thyroid levels, but it doesn't mean your child needs to be treated. If your child is obese or overweight, but otherwise healthy and growing well, the chances of hypothyroidism are very low.


Treatment is very simple. Children, whether diagnosed with congenital hypothyroidism or acquired hypothyroidism, need to take one pill a day, which replaces the amount of hormone that the thyroid is not able to produce. For babies, the pill can be crushed and put in formula, breast milk or water. There are no side effects of the medication.

Some toddlers with congenital hypothyroidism can be weaned off treatment after 2-3 years old. Children with more severe cases will need to be treated for life. Treatment for acquired hypothyroidism is also lifelong.

Why treatment is important

If not treated, congenital hypothyroidism can cause developmental delays and poor growth in babies. Adolescents and older kids may experience chronic fatigue, constant modest weight gain, poor growth, short stature, mental irregularities and learning difficulties.


Hyperthyroidism means the thyroid gland is over-reactive or produces too much thyroid hormone. The most common cause is an autoimmune disorder known as Graves’ disease. One in every 10,000 children are diagnosed with hyperthyroidism.

Symptoms and diagnosis

Children that have hyperthyroidism can have significant weight loss, rapid growth, hyperactivity, anxiety, mood swings, diarrhea or loose stools and proptosis, which is the bulging or displacement of the eyes. An enlarged thyroid gland can also be visible and can be felt, and a simple blood test can determine if the child has hyperthyroidism.


Kids with hyperthyroidism have three treatment options.

The first one is an anti-thyroid medication that normalizes the thyroid hormone levels and is given 2-3 times a day, but most children can eventually be weaned down to once a day. Side effects of the medication can include a decrease in white cell counts, high liver enzymes and skin rashes. These are monitored during treatment with blood tests.

Thyroid ablation is another option. The child swallows a pill that contains a dose of radioactive iodine, which painlessly destroys the thyroid tissue. This treatment stops the thyroid from working and the child will become hypothyroid and will need thyroid hormone replacement.

Surgery to remove the gland is the last form of treatment and is used in some cases when other treatment options cannot be considered. The child will become hypothyroid and will need thyroid hormone replacement.

Why treatment is important

Hyperthyroidism can be more serious than hypothyroidism and has more severe consequences if not treated. In rare cases, hyperthyroidism can lead to thyroid storm – a life-threatening condition that increases heart rate and blood pressure, and can cause the child’s body temperature to soar to dangerously high levels.

When treatment isn’t necessary

Sometimes when a child is tested for hyperthyroidism or hypothyroidism, the thyroid function test will come back normal, but the child can test positive for thyroid antibodies. That means the child has an increased risk of developing a thyroid disorder, but it doesn’t necessarily mean the child will develop a thyroid problem. If thyroid levels are normal, even if thyroid antibodies are present, the child does not need to be treated.

Thyroid Nodules

A thyroid nodule is a lump that develops in the thyroid gland. Nodules are relatively common in adults, but are rarely cancerous. The opposite is true for children. Thyroid nodules are rare in kids, but up to 25 percent of the cases can be malignant. Taking your child for their yearly wellness exam can help identify things like thyroid nodules early on.

Symptoms and Diagnosis

Thyroid nodules are almost always asymptomatic, which means they don’t cause noticeable symptoms. Nodules are usually diagnosed during the child’s yearly wellness exam or may be discovered when the child is having imaging done for another reason. Sometimes nodules are large enough parents may notice the growth.

Thyroid cancer is also asymptomatic and is unlike many other cancers because it usually does not cause any problems or issues for the child. It is identified after a thyroid nodule evaluation.

If your doctor identifies a thyroid nodule, they will most likely recommend a thyroid ultrasound to confirm the diagnosis. Having an enlarged thyroid gland does not mean a thyroid ultrasound should be performed, unless a thyroid nodule is felt or there is an abnormal thyroid gland on exam.


Based on the thyroid ultrasound findings and thyroid function tests, a fine needle aspiration (FNA) may be obtained. Based on the FNA results, treatment may include follow up with thyroid ultrasound, surgical removal or radioactive iodine ablation.

Find out more about how we care for thyroid nodules at Children's Mercy.

The Division of Pediatric Endocrinology and Diabetes at Children’s Mercy is nationally ranked as one of the top programs in the U.S. See how one of our pediatric endocrinologists can help your family.