Introduction

At the front of our necks, beneath the skin, we have the thyroid. The thyroid is a butterfly-shaped gland that is responsible for controlling many of our body's important functions. It does this through releasing certain hormones, specifically thyroid hormone. Our bodies carry this hormone in our blood, and it mainly affects our metabolism, meaning it controls the rate at which our food is broken down and turned into energy, for us to function properly. As a result, when our thyroid isn't working properly, people may experience symptoms such as gaining or losing weight or feeling fatigued and agitated. Thyroid problems can affect people of all ages, but are a lot more common in females over the age of 42 years and above.² 

What causes a thyroid storm? 

When your thyroid hormones elevate rapidly, this causes something known as thyroid storm, which can potentially be a life-threatening condition.¹ Furthermore, thyroid storms can lead to someone experiencing a high fever, changes in heartbeat, and other symptoms. It is not yet known what the exact underlying causes of thyroid storm however, it is known to be a rare but serious case of Hyperthyroidism and usually occurs when hyperthyroidism is left untreated. Scientists have come up with several ideas as to what may potentially cause this condition.¹

Scientists believe that stopping any thyroid medication or having thyroid surgery may be a possible cause. This is due to the effects these have on the rapid increase in the rate your body releases thyroid hormone.

Another idea scientists propose is that a thyroid storm may occur due to hyperactivity of the sympathetic nervous system. This part of the nervous system is known to control our body’s fight or flight response. Hyperactivity of this could mean an increased sensitivity to a rapid rate of release of thyroid hormones. 

Other triggering factors of trauma and stress have been identified, some of these include:²

• Infections, specifically in the lungs
• Thyroid surgery on patients with an overactive thyroid gland
• Stopping medications that treat an overactive thyroid
• Pregnancy³
• Heart attack or other cardiac emergencies 

However, a person may have elevated levels of thyroid hormone and never experience a thyroid storm, as it is a rare occurrence. 

Core symptoms of thyroid storm 

Fever

Developing a fever tends to be one of the biggest indicators of having a thyroid storm. Your body temperature can reach highs of ≥100.4°F (≥38°C). This is a key symptom of having a thyroid storm and is what helps differentiate it from hyperthyroidism. Using the above symptoms paired with an enlarged thyroid gland, protruding eyes, and a wide pulse pressure can help diagnose a thyroid storm.⁴

Tachycardia

Having a rapid heart rate is another telling sign of having a thyroid storm. Your heart rate can exceed 130 beats per minute when experiencing this condition. As a result of this, it puts a person at risk of cardiovascular complications and arrhythmias, ultimately, potentially resulting in heart failure and death through cardiac arrest.⁴

Agitation and neurological symptoms 

Central Nervous System involvement results in feelings of agitation, anxiety, and in some severe cases, risk of a seizure or coma. Signs include tremors, paralysis, and hyperreflexia - where your muscles have an overactive response; this is something that you can't control.⁵

Confusion and altered mental state

A person may experience symptoms such as confusion, delirium, and psychosis, meaning that a person experiencing a thyroid storm will show signs of altered beliefs and hallucinations or even loss of consciousness. These symptoms have been linked to hypermetabolism, in which the body is burning calories at an extremely fast rate, leading to weight loss, fatigue, and anaemia.⁶ 

Additional symptoms to look out for

• Excessive sweating
• Shortness of breath
• nausea, vomiting, and diarrhoea
• Abdominal pain 
• Chest pain
• Yellow skin or eyes (jaundice)

When to seek medical attention 

If you are experiencing any of the following symptoms, seek medical help immediately:⁷

• Fever
• Very rapid heartbeats
• Confusion and disorientation
• Significant fatigue and exhaustion

If anyone you know is experiencing any of these symptoms and they are unable to function properly, you must take them to an emergency department as soon as possible.

Treatment for thyroid storm

Medications

• Propylthiouracil (PTU) and methimazole: A patient may be administered medications to prevent the release of thyroid hormone, such as propylthiouracil and methimazole.⁴ These medications are given to slow down the rapid release of thyroid hormone into the body to alleviate any symptoms that the patient is experiencing
• Beta-blockers: A patient may be given beta-blockers to slow down their heart rate and reduce the risk of any cardiac problems from occurring^4,5,8

Supportive care

• Management of fever: Patients will be given cooling blankets and paracetamol to reduce symptoms of a fever
• Fluid replacement: Due to loss of fluids through excessive sweating, vomiting, and diarrhoea, a patient will be administered an IV drip to replace all of the lost fluids and prevent dehydration from occurring

Anyone who is admitted to the hospital for symptoms that indicate thyroid storm will be placed in an Intensive Care Unit (ICU) and treated for a life-threatening condition and, therefore, will be closely monitored and regulated. 

FAQs 

What causes thyroid storm?

It is not yet fully known by researchers why certain factors can cause thyroid storms. Thyroid storm can develop due to an untreated long-term hyperthyroidism; however, it is usually caused by an acute and sudden event.

Examples of this include:

• Suddenly stop taking your antithyroid medication
• Thyroid surgery (thyroidectomy)
• Non-Thyroid surgery
• Trauma
• Infection
• Acute illnesses such as diabetic ketoacidosis (DKA), heart failure, and a drug reaction.
• A sudden large amount of iodine in your body, such as from an iodinated contrast agent
• Giving birth
• Stroke

Can thyroid storm be fatal?

If thyroid storm is left untreated, this can be life-threatening. It is a difficult-to-diagnose, emergency medical illness with a 10% treatment-related death rate and numerous triggering variables.⁸

You should always make sure you get to the hospital immediately if you’re experiencing symptoms of thyroid storm. You should never wait for any symptoms to worsen.

What are the complications of thyroid storm?

Thyroid storm can cause serious complications, including:

• Cardiac (heart) failure
• Blood clots
• Seizures
• Delirium
• Coma

Can I prevent thyroid storm?

Thyroid storm cannot always be prevented. However, if you have hyperthyroidism, there are actions you can take to prevent thyroid storm from occurring, such as:

• Consistently taking your medication, which is given to you for hyperthyroidism, by your doctor
• Make regular visits to your doctor to ensure that your treatment is working properly
• Managing your stress

After undergoing surgery or anaesthesia, the body will produce a stress response, which can cause someone to experience thyroid storm. As a result of this, your doctor may prescribe you antithyroid medication as a preventative before having to undergo any sort of surgery. 

Summary 

Thyroid storm is a condition caused by various intense and sudden events, such as a rapid increase in the rate of thyroid hormone being released into the body; though rare, it can often be life-threatening. Examples of these events are untreated hyperthyroidism, stopping antithyroid medication, infections, thyroid surgery, or cardiac emergencies such as heart attacks and cardiac arrest. Symptoms that will arise from experiencing thyroid storm usually include an increase in heart rate (it can rise to a levels of 130 bpm), experiencing a high fever with temperatures rising to ≥100.4°F (≥38° C), agitation resulting in tremors, anxiety and even paralysis, a shortness of breath, excessive sweating, gastrointestinal symptoms such as nausea, vomiting and diarrhea, abdominal pains and even chest pains, altered mental state such as confusion and psychosis resulting in hallucinations.

If a person is experiencing any of the above symptoms mentioned above, then they must seek emergency medical help immediately. Treatment for thyroid storm often includes antithyroid medication such as PTU and methimazole to reduce the rate at which your body is releasing thyroid hormone, or beta-blockers to slow down a rapid heart rate. Additionally, supportive care will be given to patients to treat a fever, such as cooling blankets and paracetamol, or IV fluids to replace any lost fluids through vomiting and diarrhoea, to prevent dehydration. A patient experiencing thyroid storm will be placed in the ICU for close monitoring due to it being a life-threatening condition.