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Hyperthyroidism (High Thyroid Level)



  • Hyperthyroidism means that your child’s thyroid gland makes too much thyroid hormone.
  • Your child may need medicine, radiation, or surgery.
  • Make sure that your child doesn’t stop taking his or her medicine or change the way he or she takes it unless advised by the healthcare provider.


What is hyperthyroidism?

Hyperthyroidism is a condition that happens when your child’s thyroid gland makes too much thyroid hormone.

The thyroid gland is in the lower front of the neck. This gland takes iodine from the food your child eats to make thyroid hormones. Thyroid hormones are chemicals that control the way the body turns the food your child eats into energy. They also control body functions such as temperature, heart rate, appetite and emotions.

Sometimes hyperthyroidism gets better without treatment. However, a serious problem called thyroid storm can happen if your child has too much thyroid hormone. It happens most often when your child is under stress, such as with an injury, infection, or surgery. In thyroid storm, your child’s blood pressure, heart rate, and temperature can all get very high. Thyroid storm can be a life-threatening emergency. The best way to prevent it is to control hyperthyroidism.

What is the cause?

High thyroid levels may be caused by:

  • Grave's disease, which is an autoimmune disorder. This means that the body's defenses against infection attack the body's own tissue by mistake. In the case of Graves' disease, the autoimmune response changes the thyroid gland and causes it to make too much hormone. Grave’s disease most commonly affects teenage girls.
  • Thyroid nodules, which are lumps on your child’s thyroid gland that make extra thyroid hormone. Most thyroid nodules are not cancer.
  • Thyroiditis, which is swelling and irritation of the thyroid gland. Thyroiditis may be caused by a virus or bacteria. Sometimes the cause of thyroiditis is not known.
  • Taking in too much iodine from medicine or supplements.
  • Taking too much thyroid hormone to treat low thyroid levels. If your child takes thyroid hormones, you should have her thyroid levels checked as often as recommended by your provider. Also make sure your healthcare provider knows about any other medicines, herbs, or supplements that your child is taking. Some medicines and supplements can change how thyroid medicine works.
  • In rare cases, a tumor in your child’s thyroid gland or pituitary gland can cause the thyroid gland to make too much hormone. The pituitary gland is located at the base of the brain. The pituitary gland controls how much thyroid hormone is made by the thyroid gland. A tumor in your child’s pituitary gland may cause it to make too much hormone, which causes the thyroid gland to make too much thyroid hormone.

Some thyroid problems may be inherited, which means that the problem may be passed from parents to children through their genes. Genes are inside each cell of the body. They contain the information that tells the body how to develop and work.

What are the symptoms?

Symptoms may include:

  • Excessive growth or early puberty
  • Being unable to sit still (hyperactivity)
  • Trouble sleeping
  • Feeling tired, weak, or shaky
  • Being hot and sweaty, even when it is cold
  • Fast or irregular heartbeat
  • Enlarged thyroid gland (goiter) that makes your neck look swollen
  • Diarrhea
  • Weight loss despite having a good appetite
  • In Grave’s Disease, your child’s eyes may looker larger and stick out more than usual.

A thyroid storm can cause severe restlessness, confusion, sweating, and diarrhea. Your child’s heart will beat very fast, her blood pressure will get very high, and she will have a high fever. Thyroid storm is an emergency. If your child is having severe symptoms of thyroid storm, call 911 or take your child to the emergency room right away.

How is it diagnosed?

Your healthcare provider will ask about your child’s medical history and symptoms and will examine your child. Tests may include:

  • Blood tests
  • A thyroid scan that uses radioactive iodine to see how well your thyroid gland is working

How is it treated?

Treatment for hyperthyroidism depends on the cause, your child’s symptoms, and your child’s age. Treatment for hyperthyroidism lowers the amount of thyroid hormone in your child’s body. Hyperthyroidism may be treated with medicine, radiation, or surgery:

  • Anti-thyroid medicines lower the amount of thyroid hormone made by the thyroid gland. The medicine usually starts to control hyperthyroidism within a few months. Your child will likely need to keep taking the medicine for at least a year or two. Your healthcare provider may adjust your child’s dosage often during that time. Your child’s thyroid levels could go up again, even while she is taking medicine, so your child will need to have regular checkups with her healthcare provider.
  • A pill containing radioactive iodine may be used to kill thyroid cells that are making too much hormone. After this treatment, your child may need to take thyroid hormone medicine for the rest of her life.
  • If medicine and radiation do not successfully treat the problem, your child may need surgery to remove part or all of the thyroid gland. Surgery usually cures the disease, but your child will need to take thyroid hormone medicine for the rest of her life.

Medicine called beta-blockers may be prescribed to help control your symptoms. Beta-blockers do not cure hyperthyroidism, but they can make you feel better within a few hours.

Your child may be referred to a healthcare specialist who treats diseases of glands like the thyroid (endocrinologist).

Your child may be referred to an eye specialist to check for eye problems related to thyroid disease.

How can I take care of my child?

Follow the full course of treatment prescribed by your child's healthcare provider. Make sure that your child doesn’t stop taking her medicine or change the way she takes it unless your provider tells you to change or stop taking the medicine.

Your child will need to have blood tests to check thyroid hormone level every few months for the rest of her life. The tests can help make sure your child is getting the right amount of medicine.

Ask your child’s healthcare provider:

  • How and when you will hear your child’s test results
  • How long it will take your child to recover
  • If there are activities your child should avoid and when your child can return to normal activities
  • How to take care of your child at home
  • What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup. Keep all appointments for provider visits or tests.

Developed by RelayHealth.
Pediatric Advisor 2015.3 published by RelayHealth.
Last modified: 2015-07-06
Last reviewed: 2015-05-29
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.
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