MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Hyperthyroidism in Infants and Children

By

Andrew Calabria

, MD, The Children's Hospital of Philadelphia

Last full review/revision Sep 2020| Content last modified Sep 2020
Click here for the Professional Version
Topic Resources

Hyperthyroidism is increased production of thyroid hormone.

  • Graves disease is the usual cause of hyperthyroidism, but growths (nodules) on or inflammation of the thyroid gland, drugs, and infections can be causes too.

  • Symptoms depend on the child's age but typically include speeding up of bodily functions.

  • The diagnosis is based on blood tests and imaging tests.

  • Infants who are not treated until birth may have intellectual disability, growth failure, and short stature, and some may die.

  • Treatment typically includes antithyroid drugs and beta-blockers.

The thyroid gland secretes thyroid hormone. Thyroid hormone controls the speed of the body's metabolism, including how fast the heart beats and how the body regulates temperature. If the thyroid gland produces too much thyroid hormone, these functions speed up.

Locating the Thyroid Gland

Locating the Thyroid Gland

Infants

Hyperthyroidism is rare in infants but can be life-threatening. It develops in fetuses of women who have or have had Graves disease Graves disease Thyroid disorders may be present before women become pregnant, or they may develop during pregnancy. Being pregnant does not change the symptoms of thyroid disorders. How the fetus is affected... read more . In Graves disease, abnormal antibodies stimulate the thyroid gland to produce excess thyroid hormone. These antibodies may cross the placenta and stimulate the thyroid gland in the fetus, which may cause premature birth or even death. Because infants are no longer exposed to the mother's antibodies after birth, Graves disease in the newborn (neonatal Graves disease) is usually temporary, but the duration varies.

Children and adolescents

Symptoms

Symptoms of hyperthyroidism differ depending on the age of the child.

Fetuses

Symptoms of hyperthyroidism in fetuses may appear as early as the second trimester. Affected fetuses have poor growth, a very fast heart rate, and an enlarged thyroid gland (goiter Congenital Goiter Congenital goiter is enlargement of the thyroid gland that is present at birth. The enlarged thyroid gland may produce too much thyroid hormone (hyperthyroidism), too little thyroid hormone... read more ). If the disorder is present and untreated for a long period before birth, about 10 to 15% of infants die and others have impaired intellectual development Intellectual Disability Intellectual disability is significantly below average intellectual functioning present from birth or early infancy, causing limitations in the ability to conduct normal activities of daily... read more , poor growth, and short stature.

Infants

Older children and adolescents

Symptoms of hyperthyroidism reflect the speeding up of bodily functions:

  • Sleep difficulties

  • Hyperactivity

  • Sweating

  • Fatigue

  • Weight loss

  • Increased heart rate and blood pressure

  • Frequent bowel movements

  • Tremors (shakiness)

Although bodily functions increase, concentration and school performance decrease. Goiter may be present. Children may have red or bulging eyes.

Symptoms of acute thyroiditis develop suddenly. Children have tenderness over the thyroid gland, and fever. In subacute thyroiditis, these symptoms are present but are less severe and may begin after a viral illness. Fever may last for several weeks.

Complications of hyperthyroidism

Thyroid storm Thyroid storm Hyperthyroidism is overactivity of the thyroid gland that leads to high levels of thyroid hormones and speeding up of vital body functions. Graves disease is the most common cause of hyperthyroidism... read more Thyroid storm is a rare, severe complication of hyperthyroidism and a life-threatening emergency. In thyroid storm, the thyroid gland becomes suddenly and extremely active. All body functions are accelerated to dangerously high levels. Symptoms in affected children include an extremely fast heart rate, high body temperature, high blood pressure, heart failure, and changes in mental status. This disorder can lead to coma and death.

Diagnosis

  • Thyroid function tests

  • Sometimes imaging tests

In infants, doctors suspect the diagnosis of hyperthyroidism if the mother has active Graves disease or a history of Graves disease and high levels of thyroid-stimulating antibodies. To confirm the diagnosis, doctors do tests to determine levels of thyroid hormones in the blood (thyroid function tests Thyroid function tests The thyroid is a small gland, measuring about 2 inches (5 centimeters) across, that lies just under the skin below the Adam’s apple in the neck. The two halves (lobes) of the gland are connected... read more ).

In older children and adolescents, doctors do thyroid function tests. Doctors also do ultrasonography Ultrasonography Ultrasonography uses high-frequency sound (ultrasound) waves to produce images of internal organs and other tissues. A device called a transducer converts electrical current into sound waves... read more Ultrasonography on older children who have Graves disease if the thyroid gland feels asymmetric or they feel a growth (nodule) on the thyroid gland. If a nodule is found during ultrasonography, doctors remove a piece of it using a needle (called fine-needle aspiration biopsy) to determine whether the child has thyroid cancer. Doctors may also do an imaging test called radionuclide scanning Radionuclide Scanning In radionuclide scanning, radionuclides are used to produce images. A radionuclide is a radioactive form of an element, which means it is an unstable atom that becomes more stable by releasing... read more to see whether the nodule is the source of the excess thyroid hormone.

Prognosis

Infants who developed hyperthyroidism as a fetus may be severely affected if hyperthyroidism is not detected until birth. The space between their skull bones may close too soon (called craniosynostosis Craniosynostosis Craniosynostosis is a birth defect in which one or more of the skull's sutures close too early. (See also Introduction to Birth Defects of the Face, Bones, Joints, and Muscles.) The sutures... read more Craniosynostosis ) and they may have intellectual disability, growth failure, and short stature. About 10 to 15% of infants may die.

Infants who have neonatal Graves disease almost always recover within 6 months. If the mother did not take drugs that decrease the thyroid gland's production of thyroid hormones (antithyroid drugs) while pregnant, the infant will have hyperthyroidism at birth. If the mother did take the drugs while pregnant, the infant may not show symptoms of hyperthyroidism for about 3 to 7 days after birth. (See also treatment of Graves disease during pregnancy Graves disease Thyroid disorders may be present before women become pregnant, or they may develop during pregnancy. Being pregnant does not change the symptoms of thyroid disorders. How the fetus is affected... read more .)

Older children who have Graves disease may respond to antithyroid drugs or may need additional treatments to permanently treat the disorder if antithyroid drugs are not effective or if symptoms return.

Treatment

  • Antithyroid drugs

  • Beta-blockers

  • Sometimes iodine or hydrocortisone

  • Sometimes surgery

Children are given antithyroid drugs (such as methimazole), which decrease the thyroid gland's production of thyroid hormones, and beta-blockers, which are drugs that slow the heart rate. Beta-blockers are used only if the heart rate is too fast or blood pressure is too high. Treatment with beta-blockers is stopped after the antithyroid drugs have taken effect. For severe cases, such as thyroid storm, children may also be given drops of iodine by mouth or hydrocortisone by vein, but this complication is rare.

Infants who have neonatal hyperthyroidism almost always recover by 6 months and no longer need antithyroid drugs. Symptoms in older children treated with antithyroid drugs may eventually disappear (called remission), but symptoms may return (called relapse) in some children and they may need further treatment.

Sometimes children with Graves disease need additional treatments to permanently treat the disorder. Permanent treatment (definitive therapy) may be needed if the antithyroid drugs do not work (or the child does not take them) or if the drugs are causing serious side effects. In definitive therapy, the gland is destroyed with radioactive iodine or removed with surgery. However, radioactive iodine is usually not given to children who are under age 10 and is often not effective in people who have larger thyroid glands. Therefore, surgery may be done instead for children and adolescents who have these factors.

Nodules are removed surgically.

Acute thyroiditis is treated with antibiotics. Subacute thyroiditis is not treated with antibiotics, but nonsteroidal anti-inflammatory drugs (NSAIDs) are given for pain. Children are not given antithyroid drugs, but beta-blockers may be given.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Test your knowledge
Colic
Colic is the term used for a pattern of intense, excessive crying and fussing that occurs for no apparent reason in some infants. It typically begins within the first month of life. At what age does colic typically end?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP