Hyperthyroidism in children is most often due to an autoimmune condition called Graves’ disease. Treatment with medications or surgery may help reduce symptoms and bring hormone levels back into the typical range.

The thyroid is a small, butterfly-shaped gland located on the front of the neck. It produces hormones important to growth, energy, and overall health.

However, when the gland makes too much hormone — a condition known as hyperthyroidism — it can speed up the body’s processes. In children, this may lead to symptoms like rapid heartbeat, weight loss, irritability, and difficulty sleeping, among many others.

Here’s more about what causes hyperthyroidism in kids, how to recognize the symptoms, and how doctors diagnose and treat this condition.

Hyperthyroidism is the medical term for “overactive thyroid”, meaning the thyroid gland is producing too much hormone in the body.

Although this condition is more common in adults, children with certain medical situations may also develop it.

The thyroid hormones (T3 and T4) help regulate the body’s metabolism, which is how the body uses energy. When too much hormone circulates, the body’s systems speed up. This can affect how quickly the heart beats, how the body processes food, how temperature is regulated, and how the brain and muscles function.

In growing children, an overactive thyroid can interfere with growth and development, including height, weight gain, and emotional regulation.

Hyperthyroidism in children can cause a wide range of symptoms that may be subtle or that doctors may mistake for other conditions.

The symptoms may come on gradually and can range in severity from mild to severe.

Signs and symptoms may include:

Babies can also have hyperthyroidism. Signs and symptoms may be more difficult to spot in very young children, but they can include fussiness, intestinal issues, and sleep issues.

The most common cause of hyperthyroidism in children is an autoimmune condition called Graves’ disease.

With Graves’ disease, the body’s immune system mistakenly attacks the thyroid gland, causing it to produce too much hormone. In fact, Graves’ disease accounts for up to 95% of diagnoses of hyperthyroidism in children.

Graves’ disease is more common in girls and adolescents, and it may run in families. Environmental factors, like stress or infection, may also trigger it.

Other potential causes of hyperthyroidism in children may include:

Diagnosis involves a doctor taking a child’s personal and family medical history, discussing their symptoms, and doing a physical exam.

Your child’s doctor may also order tests, including:

Doctors may offer older children a radioactive iodine uptake test. The goal of this test is to see how active the thyroid gland is and to help determine the cause of excess hormone being produced.

Treatment for hyperthyroidism depends on the cause and severity of the condition. The overall goal is to regulate the amount of hormone the thyroid makes to address the symptoms.

Medication

Antithyroid drugs slow the thyroid gland’s ability to make hormones over time. This treatment is appropriate for Graves’ disease but not hyperthyroidism due to thyroiditis.

Methimazole is the only antithyroid medication approved for use in children in the United States. It may take weeks to months for methimazole to regulate hormones to typical levels, and this drug isn’t considered a cure.

Your child’s doctor may also prescribe beta-blockers to allow the blood vessels to relax and widen. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), these medications can immediately address certain symptoms — like rapid heartbeat, anxiety, and tremors — until the antithyroid drugs take full effect.

Surgery

If the condition doesn’t respond well to medication, your child’s doctor may suggest surgery to remove some or most of the thyroid gland (thyroidectomy).

Some children may develop hypothyroidism after surgery and need thyroid medication and monitoring of their hormone levels for the rest of their lives.

Radioactive iodine therapy

Older children and adolescents may have radioactive iodine therapy as part of their treatment for hyperthyroidism. This treatment, which is available orally as either a liquid or a capsule, can also treat thyroid cancer. The iodine slowly destroys the thyroid gland while not affecting other tissues in the body.

The NIDDK says that almost all people who take radioactive iodine-131 eventually develop hypothyroidism and need treatment to regulate their hormone levels for the rest of their lives.

With prompt diagnosis and treatment, the outlook for children with hyperthyroidism is generally good. Many respond well to antithyroid medications and see improvement in their symptoms. According to the American Thyroid Association, up to 25% of children who take antithyroid medications may go into long-term remission.

Most children who require surgery or radioactive iodine treatment may return to their usual activities within a few weeks.

Keeping up with regular doctor visits and managing any resulting hypothyroidism with daily medication can improve your child’s quality of life.

Make an appointment with your child’s healthcare professional if you notice any symptoms of thyroid issues.

Although hyperthyroidism in children can be challenging and may lead to complications, the condition is manageable with early diagnosis and appropriate treatment.