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Thyroid Storm: What to Know

Thyroid storm is a rare but severe form of untreated or under-managed hyperthyroidism that may arise when the thyroid gland releases thyroid hormones suddenly.

With Takashi Akamizu, MD, PhD, and Elizabeth Pearce, MD, MSc

If you have been diagnosed with an overactive thyroid, you may have concerns about thyroid storm— an extreme but very rare form of untreated (or undermanaged) hyperthyroidism.

According to recent estimates, thyroid storm—a severe form of thyrotoxicosis (or thyroid crisis)—affects less than one person in every 100,000 annually across the US population. Even so, it's crucial to know about the condition, what may trigger thyroid storm, how it should be managed, and what you can do to reduce your risk of developing it.1

Thyroid storm occurs when your thyroid gland, located at the base of your neck, releases large amounts of thyroid hormone suddenly. Your systolic blood pressure (top number, when your heart is contracting) may rise, while your diastolic (bottom number) plummets. Your heartbeat may speed up, and you may have difficulty breathing, and yellowing of the skin (jaundice). Emergency medical attention is required to avoid suffering from multiple organ failure, heart failure, or other related causes.1

Thyroid storm is an rare but extreme form of untreated hyperthyroid disease.Seeing your health practitioner at least once a year will assure your thyroid hormone levels are norrmal.

Progress in Thyroid Storm Approach to Care

Although the term thyroid storm was first used in medical studies as far back as the 1920's, information has been lacking about why it happens and how it should be treated, says Takashi Akamizu, MD, PhD, professor of medicine at Wakayama Medical University in Japan.

In a review article, published in the journal Thyroid, Dr. Akamizu summarizes previous studies and the results of surveys his team conducted in Japanese hospitals in order to compare their findings to the 2016 Japanese guidelines for managing thyroid storm.2,3  Besides providing new estimates of how often the condition occurs, it adds information for doctors on how to diagnose it and treat it. Patients with overactive thyroid should be aware of the developments, Dr. Akamizu tells Endocrine Web..1,2

Because the condition is rare, definitive information about it has been lacking, say Dr. Akamizu and other experts.

Recommendations Based on the Japanese Experience

For the first time, the proposed guidelines by this Japanese research team are based on solid evidence and were endorsed by professional organizations including the American Thyroid Association (ATA), Dr. Akamizu says. Some of the changes in treatment are at odds with the ATA guidelines, but the mainstays of management—such as needing a team of doctors to handle the crisis—are the same.1-3

The key points that Dr. Akamizu says those with hyperthyroidism need to know about thyroid storm, based on the changes to care that are presented in the review paper,1 and from his years of clinical experience are as follows:.

  • While surgical removal of the thyroid was linked to greater risk of developing thyroid storm, he says that ''nowadays, thyroidectomy itself rarely causes the storm if thyroid function is preoperatively controlled [with the strategy your doctor orders]."
  • The most common trigger for thyroid storm was an inconsistant use of prescribed antithyroid medicines or stopping the medication use without any discussion with or agreement of the doctor.
  • Infection, especially of the upper respiratory tract, was the next most common trigger.
  • Both iodine and antithyroid medications, given to normalize thyroid hormone level, can be given at the same time. Other guidelines suggest giving the drugs first, then the iodine. But Dr. Akamizu cites research findings that indicate taking both simultaneously helps thyroid levels return to normal more quickly.
  • In those with congestive heart failure, the commonly used drug, propranolol, should be used with caution.
  • Aspirin should not be taken because it could increase thyroid hormone levels above what is desirable.
  • Be aware of these signs and symptoms of thyroid storm:

o   body temperature of 100 degrees or more

o   rapid heart rate (tachycardia)

o   blood pressure over 130 (top or systolic number)

o   unusual or unexplained changes in consciousness, diarrhea, vomiting, jaundice.

While some of these conditions are more likely to point to other health concerns, if you experience some of these all at once, it is crucial to get medical help or advice.

Expert Perspective on Proposed Changes to Care

Elizabeth Pearce, MD, MSc, associate professor of medicine at Boston University School of Medicine, reviewed the new guidelines for EndocrineWeb. While the Japanese guidelines are sometimes at odds with those of the American Thyroid Association, she says both are in agreement that the mainstay of thyroid therapy should include a team of many specialists, including an endocrinologist, a cardiologist, and other specialists, and that anti-thyroid medications and other treatments are needed to normalize thyroid hormone levels.

While thyroid storm is serious and may be fatal for an estimated one in 10 patients or lead to permanent impairments for some patients, Dr. Pearce stresses the fact that it is also quite rare. 

The most important take-home message for those with an overactive thyroid?


"It is crucial to take your antithyroid medication as prescribed, and never to stop it without consulting with your healthcare provider first [as that could trigger an increase in thyroid hormone level]." And you should be sure to see your health practitioner at least once a year to have your thyroid panel checked (by a blood test) so any adjustments to your medications can be made, as needed.

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Diagnosing Hyperthyroidism: Overactivity of the Thyroid Gland