What is Hyperthyroidism?

Hyperthyroidism (overactive thyroid) occurs when the thyroid gland makes too much thyroxine, the thyroid hormone. Too much thyroid hormone increases metabolism and can cause weight loss, a rapid or irregular heartbeat, sweating, nervousness, irritability, anxiety and poor school performance.

Hyperthyroidism is relatively rare in children and adolescents. Most commonly, it is caused by Graves’ disease, which is an autoimmune disorder in which a child’s immune system attacks the thyroid gland, triggering the production of an unlimited amount of thyroxine.


  • Weight loss or difficulty gaining weight
  • Irregular or rapid heart beat
  • High blood pressure
  • Nervousness and trouble concentrating
  • Irritability
  • Bulging eyes
  • Diarrhea
  • Poor school performance
  • Swelling in the neck (goiter)


Hyperthyroidism diagnoses will begin with a physical exam and review of your child’s full medical history. In addition, our physicians may use a variety of diagnostic tests including:

  • Blood tests to measure the thyroid hormone and thyroid-stimulating hormone (TSH) levels.
  • Ultrasound, a radiation-free imaging technique, which uses high-frequency soundwaves to capture images of your child’s thyroid and lymph nodes.
  • Thyroid scan, a nuclear medicine and imaging test, in which your child drinks a radioactive iodine and then has images captured of his or her thyroid to determine how much iodine it absorbed. High iodine absorption is a sign of hyperthyroidism. Thyroid scans can also show the size, shape and position of the thyroid gland. 


At Texas Children’s Hospital, treatment plans are tailored to your child’s individual needs. Hyperthyroidism treatment may include:

  • Anti-thyroid medication: Most children will begin on anti-thyroid medication, which works to reduce the amount of thyroid hormone.
  • Radioactive iodine:An oral medication used to destroy the thyroid cells causing the excess hormone.
  • Surgery: A thyroidectomy (total removal of the thyroid) may be performed to permanently cure hyperthyroidism. These surgeries should be performed by high-volume surgical teams, such as our Thyroid Program Surgical Team, to achieve the best possible outcomes.

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