When the thyroid produces too much of thyroid hormones, it is known as hyperthyroidism. Without treatment, this can become a dangerous condition called thyroid storm.

The thyroid is a small gland at the front of the neck that produces thyroid hormones.

Thyroid storm is rare. Its incidence in the United States is between 5.7 and 7.6 per one million people.

However, thyroid storm can lead to acute heart failure and a buildup of fluid in the lungs. When it does occur, it can be life-threatening in around 10–25 percent of people with the condition.

In this article, we look at how thyroid storm develops, its symptoms, and how to treat and prevent the condition.

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A high fever is a key symptom of thyroid storm.

Without treatment for an overactive thyroid, people can develop serious health problems due to excessive thyroid hormone. These conditions can include thyroid storm, heart problems, weak and brittle bones, and may even be fatal.

Thyroid storm can occur in any person with untreated hyperthyroidism.

Situations that place stress on the body typically bring on thyroid storm. Examples of these scenarios are trauma, surgery, or severe infection.

Pregnancy and thyroid gland trauma can also trigger a thyroid storm, as well as radioactive iodine therapy for Graves’ disease and abruptly discontinuing anti-thyroid medication.

Symptoms of thyroid storm may result in a number of complications. These symptoms include:

  • high fever, sometimes above 105.8º Fahrenheit (ºF)
  • jaundice
  • goiter, or thyroid eye disease
  • dehydration
  • rapid heart rate and sometimes irregular heart rhythm
  • nausea or vomiting
  • unconsciousness
  • diarrhea
  • weakness
  • heart failure
  • confusion and agitation
  • shaking
  • sweating
  • coma

A high fever is often one of the most common signs of thyroid storm.


A thyroid storm can raise the risk of developing the following complications:

  • Atrial fibrillation: This condition causes the heart to develop an irregular rhythm, usually with a rapid ventricular rate.
  • Osteoporosis: This bone disorder makes bones weak and more prone to fracture.
  • Heart failure: The heart cannot successfully pump blood throughout the body.

These complications can all lead to ongoing health problems that can reduce quality of life.

No specific lab test can diagnose thyroid storm. Diagnosis is largely at the best judgment of the doctor after examining the clinical symptoms and signs in an individual with hyperthyroidism.

To diagnose thyroid storm, the doctor will look to identify any common symptoms of hyperthyroidism, such as high temperature, fast heart rate, nausea and vomiting, or confusion.

A doctor will likely order blood tests as part of the evaluation to look for high levels of thyroid hormones (free T4 and free T3) in the blood.

The thyroid-stimulating hormone (TSH) test will show a low level of TSH and can also provide information about what is happening in the body.

Thyroid storm is a very dangerous condition. In many cases, waiting on blood test results may cost vital moments when the doctor could be administering aggressive treatment.

It is likely, therefore, that medical treatment will start immediately. Even so, the condition can still be dangerous, especially for older adults.

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Eating too much food that contains iodine, such as seaweed, can increase the risk of thyroid storm.

The underlying cause of thyroid storm is hyperthyroidism, which is a thyroid disorder.

Hyperthyroidism occurs when the thyroid makes too much of the hormone thyroxine. An overactive thyroid can cause many body functions to speed up.

Many different conditions can cause or worsen hyperthyroidism, including:

  • Graves’ disease, an autoimmune disease that attacks the thyroid gland
  • viral infections, other autoimmune conditions, or the stress of childbirth, can all inflame the thyroid
  • overactive thyroid nodules
  • tests that use iodine
  • eating too many foods that contain iodine
  • consuming large amounts of thyroid hormone
  • certain tumors of the ovaries or testes

Hyperthyroidism shares many symptoms with other health problems. Also, some people may not have any symptoms at all, which makes the disorder even more difficult to pinpoint.

Treatment for hyperthyroidism depends on a person’s age, the cause, the severity of the illness, and any other medical conditions the individual may have.

Thyroid storm requires emergency treatment, usually in an intensive care unit setting.

In many cases, the right treatment regime produces improvement of thyroid storm within 24 hours. The time to resolution of symptoms will likely depend on individual factors that led to the person experiencing thyroid storm and may take up to one week.

Treatment options include:

Thyroid storm is a medical emergency. Any person who experiences symptoms of thyroid storm should seek immediate medical treatment from a health professional.

In addition to adhering to the therapy plan that their doctor prescribes, people with an overactive thyroid can help control their disorder by eating well, exercising, and keeping their stress to a minimum.

The best way to prevent thyroid storm, however, is to address and treat the cause of hyperthyroidism correctly.

Proper treatment of hyperthyroidism is vital to making sure that the body functions normally, but also to preventing the onset of thyroid storm.

A person can prevent thyroid storm by treating and controlling an overactive thyroid and following their doctor’s instructions.

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The thyroid can influence how fast a person burns calories, the speed of their heart rate, and their breathing rate.

Thyroid hormones help the body use energy and control a number of activities. They influence how fast the body burns calories, a person’s breathing rate, gastrointestinal activity, and even how fast their heart beats.

These hormones also play a role in processes that include helping the body stay warm and maintaining energy usage in the brain, heart muscles, and other organs.

A small gland in the brain called the pituitary gland helps to control thyroid hormone levels in the body. The pituitary gland makes thyroid-stimulating hormone (TSH), which stimulates the thyroid gland to produce thyroid hormones.

TSH levels in the bloodstream rise or fall depending on whether enough hormones are circulating to meet the body’s needs. As thyroid hormone levels go up or down, the pituitary gland drops or raises TSH production in response.

When either of these glands releases too many or too few hormones, thyroid disorders can occur.

Both overactive and underactive thyroid glands can lead to various serious health problems. According to the University of California, San Diego Health Center, around 20 million people in the U.S. currently have some form of thyroid disease.

Thyroid storm is a rare but potentially dangerous consequence of an overactive thyroid gland, which is known as hyperthyroidism.

Signs and symptoms of thyroid storm need immediate medical attention to prevent serious and sometimes life-threatening consequences.