Thyroid storm (thyroid crisis) is a potentially life-threatening condition for people who have hyperthyroidism. Thyroid storm happens when your thyroid gland suddenly releases large amounts of thyroid hormone in a short period of time. If you have thyroid storm, you will need emergency medical treatment. Thyroid storm is more likely to develop when a person has a serious health problem in addition to hyperthyroidism or in people who have untreated or undertreated Graves’ disease. The problem usually happens after a stressful event or a serious illness, such as a major infection. It may also be triggered by surgery or by using iodine for a CT scan or in radioactive iodine therapy.
It is characterized by a high fever (often above 40°C/104°F), fast and often irregular heart beat, vomiting, diarrhea and agitation. Heart failure may occur, and myocardial infarction is encountered. Death may occur despite treatment. Most episodes occur either in those with known hyperthyroidism whose treatment has been stopped or become ineffective, or in those with untreated mild hyperthyroidism who have developed an intercurrent illness (such as an infection). The severity of hyperthyroidism, thyrotoxicosis and thyroid storm can be assessed with the Burch-Wartofsky score, first introduced in 1993. A score is derived from various clinical parameters (such as temperature, severity of agitation);
a score below 25 excludes thyroid storm, 25–45 suggests impending storm, and above 45 is suggestive of thyroid storm. Thyroid storm requires prompt treatment and hospitalization. Often, admission to the intensive care unit is needed. Inorganic iodide (ideally potassium iodide and not Lugol’s iodine) and antithyroid drugs (methimazole or propylthiouracil) are used to reduce the release of thyroid hormone from the gland, and beta blockers to reduce the effect of circulating thyroid hormone on end organs. In high fever, temperature control is achieved with paracetamol/acetaminophen, and frequently fluid replacement, mechanical ventilation and corticosteroids. Any suspected underlying cause is also addressed.
One should not overlook the following symptoms if they are present –
- High fever of 100 to as high as 106
- A high heart rate that can be as high as 200 beats per minute
- Palpitations, chest pain, shortness of breath
- High blood pressure
- Confusion, delirium and even psychosis
- Extreme weakness and fatigue
- Extreme restlessness, nervousness, mood swings
- Exaggerated reflexes
- Difficulty breathing
- Nausea, vomiting, diarrhea
- Recent dramatic weight loss may have taken place recently
- Profuse sweating, dehydration
- Stupor or coma
It’s thought that physical or mental stress can lead to thyroid storm because stress causes high levels of certain hormones to be released into the bloodstream. People with hyperthyroidism seem to be particularly sensitive to these hormones — adrenal hormones like dopamine, epinephrine (adrenaline), and norepinephrine, for instance — which can have the effect of putting all body systems into high gear. Combine those hormones with the high levels of thyroid hormone present in someone with undiagnosed or untreated Graves’ disease, and you have a flood of substances that can cause overactivity in nearly all body systems.
Thyroid storm must be treated immediately and aggressively, usually requiring admittance to an intensive care unit. If it’s left untreated, heart failure, difficulty breathing, or coma may result.