Hyperthyroidism In Children: Symptoms To Watch Out For

Hyperthyroidism affects about 1 out of every 100 people over the age of 12¹ in the United States. Only 1 out of every 100,000 children² develop the condition, making it very uncommon in childhood.

You are more likely to develop hyperthyroidism as you get older, especially if you have a family history of the condition. However, this medical condition can affect people of any age, including infants.

Children with hyperthyroidism may experience symptoms such as unexplained weight loss, anxiety, excessive sweating, and an inability to concentrate. The disease may also affect their development, especially if it remains untreated in infants.

Hyperthyroidism is extremely rare in infants, and there are only four documented cases of children under age 2 developing Graves’ disease (a common cause of hyperthyroidism).

If you are concerned that your child may have hyperthyroidism, learn more about its signs and symptoms in children. You should also know when to make an appointment with their primary care clinician and some of the available treatment options.

What is hyperthyroidism?

Hyperthyroidism is a disorder affecting the thyroid gland. This gland, which is part of your endocrine system, sits at the front of the neck and covers the trachea. The thyroid’s function is to create hormones that help your body manage how it uses and stores energy. These hormones impact your heart rate, respiration, metabolism, and many other functions in the body.

Sometimes, the thyroid produces more hormone than the body actually needs. This is known as hyperthyroidism. The prefix hyper- means overactive, so the word hyperthyroid means an overactive thyroid gland. It can cause symptoms such as fatigue, unexplained weight loss, tremor, bulging eyes, and irritability.

There are several reasons you may have an overactive thyroid, including:

• Graves’ disease

• Thyroiditis, or inflammation of the thyroid

• Having a diet high in iodine-rich foods

• A tumor on your pituitary gland that sends messages to the thyroid to produce hormones

Hyperthyroidism is a treatable condition. Most people can bring their thyroid hormone levels into the normal range through medication and radioiodine therapy while implementing certain lifestyle changes. In more severe cases, surgery may also be an option.

Is hyperthyroidism different for children?

Children will exhibit many of the same symptoms as adults when they have hyperthyroidism. The biggest difference is the importance of catching and treating the condition as early as possible.

Hyperthyroidism can cause developmental delays in children,² including failure to thrive in infants. The condition is relatively rare in infants and is most often a concern when the mother has hyperthyroidism.

Hyperthyroidism affects about 1 out of every 5,000 children and adolescents,³ with one UK study showing 96% of pediatric hyperthyroidism cases⁴ were attributable to Graves’ disease.

Other causes may include toxic adenoma, Hashitoxicosis, and drug-induced thyrotoxicosis. Hyperthyroidism is more common in girls, and there is an increased incidence during puberty.

Symptoms of hyperthyroidism in children

It can be difficult to diagnose hyperthyroidism in children. The disorder shares symptoms with other common medical conditions, including anxiety and certain blood disorders. Pediatric Graves’ disease can also present with hyperactivity.⁵ However, a doctor can conclusively diagnose hyperthyroidism with a blood test.

Children generally experience the same symptoms of hyperthyroidism as adults do, including:

• Unexplained weight loss, often despite an increase in appetite

• Feeling nervous, anxious, or irritable 

• Frequent need to empty the bowels

• Tremors in the hands 

• Swelling in the neck, also known as goiter

• Excessive sweating or intolerance of heat

• Infrequent or missed menstrual periods

• Inability to concentrate 

• Weak muscles 

• Smooth and shiny skin

If the hyperthyroidism is due to Graves’ disease, the child may also have redness or swelling around the eyes, or the eyes might look like they are bulging due to swelling in the surrounding tissue.

If symptoms go untreated, in rare cases, a child might go on to experience what’s called a thyroid storm. This can happen when thyroid hormones reach dangerously elevated levels.

Symptoms of thyroid storm include a spike in fever, rapid heartbeat, mental confusion, and diarrhea. These patients require immediate medical attention, so don’t hesitate to take your child to the nearest emergency department or call 911.

What’s the difference between hypothyroidism and hyperthyroidism in children? 

Hyperthyroidism is a medical condition that results from a hyperactive thyroid gland that produces an excess of hormones.

Hypothyroidism occurs when the thyroid gland isn’t producing enough of its hormones. Its symptoms include fatigue, unexplained weight gain, constipation, intolerance of cold temperatures, and dry skin. Both conditions are treatable.

How is hyperthyroidism in children diagnosed?

A hyperthyroidism diagnosis usually starts with making an appointment with your child’s pediatrician or another primary clinician. First, they will ask about your child’s symptoms and perform a physical examination to evaluate for any other underlying medical conditions.

Next, they may request a blood test specifically to assess: 

Thyroid hormone levels 

There are two thyroid hormone types, T3 and T4. Elevated levels would indicate your child might have hyperthyroidism. 

Thyroid-stimulating hormone (TSH) levels

This hormone comes from the pituitary gland and signals the thyroid to make more of its hormones. Low TSH levels indicate the thyroid doesn’t need stimulation because it is producing too much of the hormone on its own.

The results of these blood tests can help the doctor diagnose hyperthyroidism. If your child receives this diagnosis,  more testing will probably be needed to determine the underlying cause and if there are any associated medical conditions.

These results can help guide their treatment plan. Your child may also be referred to a pediatric endocrinologist, a specialist in hormone-related conditions.

What are the treatment options for children with hyperthyroidism?

Hyperthyroidism doesn’t go away on its own, and some children will need ongoing care throughout their lives to manage their thyroid disorder. However, with the right treatment, most go on to live healthy and happy lives with minimal effects.

When determining the best treatment options for a child with hyperthyroidism, the doctor will consider their age, the cause of their hyperthyroidism, and the severity of their condition.

Common treatment options include the following. 

Medication

Antithyroid medications work to lower thyroid hormone levels in the body, while beta-blockers can help reduce the effects of too much thyroid hormone. After taking antithyroid medication, around 30% of children will go into remission;⁶ their thyroid hormone production normalizes, and they have no more symptoms of hyperthyroidism.

There is new research⁷ into the treatment of pediatric Graves’ disease with immune-modulating medications, treating an immune attack with an immunosuppressant. These therapies are still in the investigative stages. If pediatric patients don’t go into remission after a few years of taking medications or if they have an adverse reaction to antithyroid medications, their healthcare team may recommend radioiodine therapy or a surgical option.⁸ 

Radioiodine therapy

This treatment involves taking a very low dose of radioactive iodine, which is then absorbed by the thyroid. The thyroid gland will shrink over time, making it less effective at producing thyroid hormones and, in most cases, stops its hormone production completely.

That’s why children who undergo this type of treatment develop hypothyroidism. Thyroid hormone replacement therapy will be given to bring their levels back into the normal range. They will need to remain on this medication for the rest of their life. 

Surgery

In severe cases, surgery may be the best option to get hyperthyroidism under control. The surgeon will remove part or all of the thyroid gland to prevent it from producing hormones. This will also result in life-long hypothyroidism, a condition easily managed with thyroid hormone replacement.

For pediatric patients with thyroid conditions, treatment will often require a multidisciplinary approach,⁹ with multiple doctors working together to provide the best care. This team usually includes the patient’s pediatrician, endocrinologist, ophthalmologist, radiologist, and surgeon.

In children, antithyroid medication is often given as the first-line treatment, but it doesn’t usually provide a long-term solution with remission. Many cases will require either radioactive iodine or surgery as the definitive treatment.

When to see a doctor about your child’s symptoms

Because of the impact that a thyroid disorder can have on their development, newborns are routinely screened at birth. Thanks to this testing, most congenital hyperthyroidism is diagnosed and treated in the newborn period.

However, hyperthyroidism can develop in children and teens of any age. Girls are more at risk than boys, but the risk increases for both genders if thyroid conditions run in the family.

If your child is showing any of the symptoms of hyperthyroidism, such as the ones described above, make an appointment with their pediatrician or another primary healthcare professional for an evaluation. Blood tests will help determine if your child has hyperthyroidism or another medical condition that requires treatment.

If your child is running a high fever, acting confused, or experiencing extreme weakness, bring them to the emergency department immediately or call 911.

The lowdown

Hyperthyroidism is a disorder of the thyroid gland, which secretes a hormone responsible for how your body uses and stores energy. The condition can occur at any age and is present in about 1% to 2% of the pediatric population.

Hyperthyroidism is more commonly seen in teenagers than young children. While it’s rare in infants, it can impact their cognitive development and requires treatment.

In children with hyperthyroidism, the thyroid is producing an excess of these hormones. This results in symptoms such as weight loss, fatigue, muscle tremors, and frequent stooling. Children and adolescents who develop hyperthyroidism may sleep less, lose weight even though they are eating more, or become more sensitive to heat.

Doctors can diagnose hyperthyroidism with blood tests and may do additional testing to determine an underlying cause. There are many treatment options for children, including medication, radioactive iodine therapy, and surgery.

Most children can live happy and healthy lives with the right treatment. If your child is exhibiting any signs of hyperthyroidism, make an appointment with their primary healthcare professional to discuss their symptoms.