Introduction

Thyroid storm is a life-threatening complication of hyperthyroidism, an emergency condition caused by the sudden release of large amounts of thyroid hormones into the body. Thyroid storm may be caused by an increase in thyroid hormone levels or thyroid-stimulating hormone (TSH) releasing tumours. Thyroid storm typically occurs in people with uncontrolled Graves' disease,¹ but it can also be triggered by stopping treatment for hyperthyroidism, infection, thyroid/non-thyroid surgery, childbirth, trauma, exposure to iodine, or long-term use of certain medications. Early detection is crucial to help prevent serious organ damage that could be life-threatening.

Causes

The thyroid gland in the neck activates hormones which control and regulate energy, heart rate, and temperature in the body. An overactivity of these glands causes high levels of thyroid hormones in the body, leading to hyperthyroidism. In some emergency cases, Thyroid storm may occur due to:

• Graves' disease - an autoimmune disorder which causes an excess production of thyroid hormones what the body needs.
• Increased amount of free T3 (triiodothyronine) and T4 (thyroxine) hormones in the blood
• Thyroid nodules or tumours
• Goitre, which is defined as an abnormal swelling of the thyroid glands
• Drugs - certain medications such as NSAIDs, chemotherapy, anticholinergic drugs, and salicylates.
• Thyroiditis -  inflammation of the thyroid
• Too much iodine intake - Certain medications can trigger thyrotoxicosis (a dangerously high level of thyroid hormones), which may lead to thyroid storm. These include iodine‐containing medications such as amiodarone (a heart medication) or large doses of topical povidone–iodine (commonly used as an antiseptic). Amiodarone contains a high level of iodine, which can raise iodine levels in the body and trigger thyroid storm in susceptible individuals⁹
• Pituitary disorders or tumours, including Cushing's disease and Acromegaly

Clinical criteria for diagnosis

The diagnosis of thyroid storm is based mainly on clinical judgment. While scoring systems can help guide the process, doctors rely most on the patients’ symptoms and overall clinical presentations. Figures 1 and 2 below showcase these clinical presentations.

The Burch-Wartofsky Point Scale is the most recognised scoring system that assigns points for the diagnosis of Thyroid Storm. It uses clinical signs and symptoms, temperature, central nervous system manifestations, cardiovascular symptoms, gastrointestinal symptoms, and precipitating factors. A total score exceeding a certain threshold indicates the presence of a thyroid storm.³

Key symptoms of thyroid storm

High Fever- > 40°C or 104°F

• Tachycardia - Having an elevated heart rate > 140 bpm
• Atrial Fibrillation - Irregular heartbeat
• Dyspnea - Shortness of breath
• Altered mental status (delirium, agitation, confusion, or coma).
• Gastrointestinal symptoms - Such as nausea, vomiting, diarrhoea
• Profound weakness, dehydration, and heat intolerance
• Hypertension - Elevated blood pressure
• Chest pain
• Agitation or confusion
• Fluid in the lungs
• Excessive sweating
• Tremors in the hands and feet
• Dizziness or fainting
• Shortness of breath
• Cyanosis
• arrhythmias
• Jaundice⁷
• ophthalmopathy

Laboratory and diagnostic tests

• Complete blood count (CBC): Checks levels of red blood cells, platelets, and markers of infection, like a high white blood cell count
• Electrocardiogram (ECG): Measures the heart's electrical activity for any cardiac abnormalities such as tachycardia, arrhythmia or atrial fibrillation
• Imaging scan: Ultrasounds, chest X-rays, or computed tomography (CT scans) are used to look for signs of inflammation or changes in the size of organs in the head, neck, or chest
• Liver function test: Evaluate levels of liver enzymes, protein levels, Blood Urea Nitrogen (BUN) and bilirubin, to check how well the liver is working
• Electrolyte abnormalities - Low sodium (hyponatremia) and high calcium (hypercalcemia) can exist due to bone breakdown and dehydration
• Acute Kidney Injury - Dehydration can lead to elevated BUN/creatinine levels
• Elevated glucose - This can be caused by stress and increased cortisol levels
• Thyroid test: Assesses thyroid-stimulating hormone (TSH), T3, and T4 levels in your body

Differential diagnosis

• Conditions Mimicking Thyroid Storm:
  • Leukocytosis: May indicate a concomitant infection; however, it can also be present even in the absence of infection.¹⁰ Often presents with fever, tachycardia, and altered mental status.
  • Pheochromocytoma: Can present with hypertension, tachycardia, and hyperthermia.
  • Heat stroke: Elevated temperature, tachycardia, and altered mental status, but no thyroid abnormalities.
  • Delirium: Seen in cases of severe infection and drug toxicity
  • Cardiac arrhythmias: Can present with tachycardia and altered mental status 

• Thyroid Conditions to Rule Out:
  • Graves' disease -As an underlying cause of thyroid storm
  • Subacute thyroiditis: Could present with fever and tachycardia, but not due to elevated thyroid hormones. Usually caused by viruses, which can inflame the thyroid glands, causing an infection.

Treatment 

• Fluid and electrolyte replacement
• Oxygen therapy
• Cardio- support as needed
• Antibiotics
• Acetaminophen, NSAIDs or cooling blankets therapy for elevated temperature
• Beta-blocking agents - Such as Propranolol and Esmolol. Used for elevated heart rate (tachycardia) 
• Antithyroid medications - Such as Methimazole and Propylthiouracil
• Potassium iodide - Typically given one hour after the first dose of antithyroid medication
• Steroids - Hydrocortisone can help alleviate inflammation
• Plasmapheresis
• Dialysis
• Surgery
• Oral T4 and T3 binding-resin medications such as Colestipol or Cholestyramine 

Summary

Making an immediate, accurate and timely diagnosis of thyroid storm is crucial to ensure effective treatment, to avoid severe complications and to support the best possible outcome. Prevention is always the best approach, and this starts with educating patients about the factors that can trigger an episode, such as discontinuing anti-thyroid medications, and helping them recognise and respond to critical symptoms early.

Knowing the signs of thyroid storm and acting quickly can make all the difference in protecting your health.