What are the symptoms of a thyroid storm (hyperthyroid crisis)?

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From the Guidelines

Thyroid storm, also known as hyperthyroid crisis, is characterized by severe symptoms including fever, tachycardia, altered mental status, vomiting, diarrhea, and cardiac arrhythmia 1.

Key Symptoms

  • Fever: a high body temperature
  • Tachycardia: a rapid heart rate
  • Altered mental status: nervousness, restlessness, confusion, seizures
  • Gastrointestinal symptoms: vomiting, diarrhea
  • Cardiac arrhythmia: irregular heart rhythm These symptoms can be triggered by an inciting event such as surgery, infection, labor, or delivery 1.

Diagnosis and Treatment

Diagnosis is based on a combination of signs and symptoms, as well as serum-free triiodothyronine (FT3), FT4, and TSH levels 1. Treatment typically involves a standard series of drugs including propylthiouracil or methimazole, saturated solution of potassium iodide or sodium iodide, dexamethasone, and phenobarbital 1. General supportive measures such as oxygen, antipyretics, and monitoring are also important 1.

Associated Conditions

Thyroid storm can also be associated with atrial fibrillation, which occurs in 10-25% of patients with hyperthyroidism, especially in men and the elderly 1. In these cases, β-blockers may be effective in controlling the ventricular rate, and non-dihydropyridine calcium channel antagonists such as diltiazem and verapamil may be used as alternatives 1.

From the Research

Symptoms of Thyroid Storm

The symptoms of thyroid storm, also known as hyperthyroid crisis, can be severe and life-threatening. Some of the common symptoms include:

  • Fever 2
  • Tachycardia [(2,3,4,5)]
  • Signs of congestive heart failure 2
  • Vomiting/diarrhea 2
  • Hepatic dysfunction [(2,6)]
  • Central nervous system disturbance 2
  • Hyperthermia [(2,6,4,5)]
  • Agitation [(2,4)]
  • Altered mental status 4
  • Anxiety 5
  • Gastrointestinal disturbances 5
  • Elevated heart rate 5
  • Changes in mental status 5

Clinical Presentation

Thyroid storm can present with a variety of symptoms, and its diagnosis can be challenging due to the lack of specific laboratory investigations or universally accepted criteria 3. The clinical presentation of thyroid storm is often characterized by exaggerated signs and symptoms of thyrotoxicosis and evidence of multiorgan decompensation 2.

Cardiovascular Manifestations

Cardiovascular manifestations are common in thyroid storm, and cardiac involvement can be the most serious complication 3. Atrial fibrillation 4 and heart failure [(3,5)] are some of the cardiovascular manifestations that can occur in thyroid storm. Management of cardiovascular manifestations should be aggressive to prevent long-term myocardial damage 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

High risk and low prevalence diseases: Thyroid storm.

The American journal of emergency medicine, 2023

Research

Atrial fibrillation from thyroid storm.

The Journal of emergency medicine, 2012

Research

Thyrotoxicosis.

Emergency medicine clinics of North America, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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