Thyroid Disease Hyperthyroidism Thyroid Storm: Symptoms and Care After an Attack Life-Threatening Condition Requires Immediate Medical Attention By Mary Shomon Updated on October 11, 2023 Medically reviewed by Ana Maria Kausel, MD Fact checked by Zerah Isaacs Print Table of Contents View All Table of Contents Symptoms Causes and Risk Factors Diagnosis Treatment Prognosis A thyroid storm, also called thyrotoxic crisis, is a rare but potentially life-threatening condition due to extremely high levels of thyroid hormone. It's most often due to an existing hyperthyroidism disorder (overactive thyroid gland) like the autoimmune condition called Graves' disease. Other factors, like infection, also may contribute to the risk. A thyroid storm can have an instant effect on your body. Following a thyroid attack, symptoms you might encounter include: Uncontrolled hypertension (high blood pressure) A racing or irregular heart rate A high body temperature Digestive system changes, like diarrhea or jaundice This article explains thyroid attack symptoms, causes, and risk factors. It discusses how a thyroid storm is diagnosed and why aggressive treatment is necessary to try to prevent the worst outcomes. Illustration by Laura Porter for Verywell Health Symptoms of Thyroid Storm Symptoms of thyroid storm are usually quite extreme and include: A very high fever of 100 to 106 degrees A very high heart rate, which can be as high as 200 beats per minute (BPM) Palpitations, chest pain, and shortness of breath High blood pressure Confusion, delirium, and even psychosis Extreme physical and muscle weakness Extreme fatigue and exhaustion Extreme restlessness, nervousness, and mood swings Exaggerated reflexes, especially in knee and ankle areas Nausea, vomiting, and diarrhea Profuse sweating or dehydration Stupor or coma Recent dramatic weight loss Complications of thyroid storm include stroke and heart attack, which can lead to death. When to Go to the ER Whenever thyroid storm is suspected, you must go to the emergency room immediately. Thyroid storm requires immediate treatment, as it is life-threatening and can develop and worsen quickly. Causes and Risk Factors The primary risk factor for thyroid storm is underlying hyperthyroidism, such as with untreated Graves' disease. There's also evidence to suggest that a thyroid storm can occur with an Epstein-Barr virus infection. People diagnosed with COVID-19 also may experience a thyroid storm. Even when the underlying disease is identified and being treated, there are a number of other factors that raise your risk of thyroid storm: Infection, specifically lung infections, throat infections, or pneumonia Recent surgery on your thyroid gland or trauma to your thyroid Abrupt withdrawal of your thyroid medications Radioactive iodine (RAI) treatment of your thyroid Excessive palpation (handling/manipulation) of your thyroid gland Exposure to a large quantity of iodine (such as an iodine-based contrast agent or the heart drug amiodarone) Severe emotional stress An overdose of thyroid hormone drugs Toxemia of pregnancy and labor In rare cases, even an aspirin overdose can lead to a thyroid storm. What Happens to Cause a Thyroid Storm? With thyroid storms, the thyroid usually produces an extreme amount of the key hormones involved in thyroid function—triiodothyronine (T3) and thyroxine (T4). This can cause your heart rate, blood pressure, and body temperature to become uncontrollably high. Causes and Risk Factors of Hyperthyroidism Diagnosing a Thyroid Storm Healthcare providers have developed a scoring system that helps them quickly assess symptoms and make a presumptive diagnosis of thyroid storm, so they can rapidly begin treatment. The system involves measuring: TemperatureHeart rateGastrointestinal symptomsNeurological symptomsWhether the patient has had a previous thyroid storm Sometimes, blood tests are done to look for high levels of thyroid hormones. A TSH (thyroid stimulating hormone) test may also be done. Because thyroid storm is a medical emergency, however, there is rarely time to wait for test results and treatment is started immediately. Thyroid Testing and Diagnosis Thyroid Storm Treatment When treating thyroid storm, healthcare providers typically use multiple interventions meant to interfere with the excessive thyroid hormone levels causing it. Treatment includes: Blocking the synthesis of thyroid hormone using antithyroid drugs. This is typically done right away with larger initial loading doses and frequent administration of additional doses. In patients who can't tolerate antithyroid drugs, lithium is sometimes used. Blocking the release of thyroid hormone using a potassium iodide preparation. This is usually given after the antithyroid drugs. Blocking T4 to T3 conversion using a corticosteroid drug, such as hydrocortisone Use of a beta-blocker drug, such as propranolol, to reduce blood pressure and heart rate Supportive treatment may also include cooling to help reduce body temperature, fluids to combat dehydration, and treatment of any other infections. Typically, if the treatments are going to work, the improvement will be seen within 48 hours. When thyroid storm does not respond to these approaches, plasmapheresis, a blood filtering treatment, is sometimes done to remove thyroid hormone from the bloodstream. In rare cases, the thyroid is surgically removed. How to Take Your Thyroid Medication Prognosis A thyroid storm may not occur with each person diagnosed with excessively high thyroid levels, also called thyrotoxicosis (which can be treated with medication or even surgery). One study reported 16% of those hospitalized with thyrotoxicosis have a thyroid storm. Those with thyrotoxicosis and a thyroid storm have higher mortality rates than those with just thyrotoxicosis. However, treatment is the key. The mortality rate in people whose thyroid storm goes untreated ranges from 80% to 100%. When treated, thyroid storms prove fatal in less than half of cases, with some studies suggesting a rate as low as 10%. Prognosis also depends on underlying age and health. Outcomes are less positive for people who experienced coma with a thyroid storm. Poor outcomes also are associated with thyroid storms that involve cardiac events including arrhythmia and heart failure, with a greater risk in people with underlying obesity, chronic obstructive pulmonary disease (COPD), and liver disorders. Summary While a thyroid storm is rare, it is life-threatening. The symptoms of rapid heart rate, very high blood pressure, and extremely high body temperature are usually related to an underlying hyperthyroidism such as Graves' disease. A thyroid storm needs to be diagnosed and treated immediately, typically with medications used to block thyroid hormone activity and lower the body's vital signs. If left untreated, 80% or more of thyroid storm cases prove fatal. The potential for an underlying thyroid disorder is one good reason to keep up-to-date on your routine healthcare exams. Your healthcare provider can feel your thyroid to check if it's enlarged (a sign of hyperthyroidism) and order annual blood tests. They can ensure any treatment plan you need is designed to manage thyroid disease. 9 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Ylli D, Klubo-Gwiezdzinska J, Wartofsky L. Thyroid emergencies. Pol Arch Intern Med. 2019;129(7-8):526-534. doi:10.20452/pamw.14876 Idrose AM. Acute and emergency care for thyrotoxicosis and thyroid storm: Management of thyroid storm. Acute Medicine & Surgery. 2015;2(3):147-157. doi:10.1002/ams2.104 Albehair MA, Alagga AA, Ghulam WZ, Alomair AM, AlFaraj D. Thyroid Storm: Unusual Presentation and Complication. Cureus. 2021 Jan 4;13(1):e12483. doi:10.7759/cureus.12483 Lania A, Sandri MT, Cellini M, Mirani M, Lavezzi E, Mazziotti G. Thyrotoxicosis in patients with COVID-19: the THYRCOV study. 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