Thyroid Storm vs Thyrotoxicosis: Differences

Medically Reviewed on 7/8/2022
Thyroid Storm vs Thyrotoxicosis: Differences
A thyroid storm or crisis is a rare endocrine emergency that represents the extreme manifestation of thyrotoxicosis.

The thyroid is a butterfly-shaped gland located in the front of the neck that produces and releases two hormones: triiodothyronine (T3) and thyroxine (T4).

These hormones play a crucial role in several important bodily functions, such as maintaining:

  • Body temperature
  • Heart rate
  • Metabolism

What is thyroid storm vs thyrotoxicosis?

Thyroid storm

A thyroid storm or crisis is a rare endocrine emergency that represents the extreme manifestation of thyrotoxicosis (severe thyrotoxicosis).

  • Although Graves’ disease is the most common underlying disorder in thyroid storms, presentation is usually triggered by a precipitating event, such as an acute infection, trauma, or a surgical procedure.
  • A thyroid storm is a life-threatening complication of hyperthyroidism in which the thyroid suddenly produces and releases a large amount of thyroid hormone in a short amount of time.


Thyrotoxicosis is a rare treatable condition that occurs due to excess thyroid hormone in the body that could be due to hyperthyroidism (production and release of excess thyroid hormones) and excess consumption of thyroid medications.

  • The likelihood of thyrotoxicosis increases as age progresses.
  • Females are more commonly affected by thyrotoxicosis than males.

What are the symptoms of thyroid storm vs thyrotoxicosis?

Thyroid storm

This condition is rare, can be life-threatening, and requires immediate medical attention.

Symptoms of thyroid storm (severe thyrotoxicosis) include:


Common symptoms of mild and moderate thyrotoxicosis include:

  • Unexplained weight loss
  • Rapid heartbeat (tachycardia)
  • An irregular heartbeat (arrhythmia)
  • Muscle weakness
  • Nervous, anxious, or irritable
  • Shakiness
  • Increased sensitivity to heat
  • Changes in menstruation

How are thyroid storm and thyrotoxicosis treated?

Thyroid storm

Treatment of thyroid storm involves:

  • Decreasing new hormone synthesis
  • Inhibiting the release of thyroid hormone
  • Blocking the peripheral effects of thyroid hormone
  • The multidrug, therapeutic approach includes thionamides, iodine, beta-adrenergic receptor antagonists, corticosteroids in certain circumstances, and supportive therapy
  • Certain cases may warrant the use of additional therapy with cholestyramine, lithium carbonate, or potassium perchlorate


Treatment for thyrotoxicosis depends on the cause and the options may include:

  • Antithyroid drugs: Tapazole (methimazole) and propylthiouracil.
  • Radioactive iodine: Oral intake of radioactive iodine makes the overactive thyroid cells absorb the iodine which damages the cells causing the shrinkage of the thyroid gland.
  • Surgery: Removal of the thyroid gland (thyroidectomy).
  • Beta-blockers: Regulate the heartbeat.
  • Glucocorticoids: A type of corticosteroid prescribed to treat thyroiditis.


Hyperthyroidism: Symptoms, Treatment, Medication See Slideshow

Key differences between thyroid storm and thyrotoxicosis

Table. Key differences between thyroid storm and thyrotoxicosis
Differences Thyroid storm Thyrotoxicosis
Causes A complication of thyrotoxicosis of any etiology precipitated by stress, infections, surgery, trauma, or heart attack
  • Hyperthyroidism
  • Graves’ disease
  • Thyroiditis (thyroid inflammation)
  • Excess thyroid medications
  • Hamburger thyrotoxicosis
Risk factors
  • Sepsis
  • Surgery
  • Anesthesia induction 
  • Radioactive iodine (RAI) therapy
  • Drugs (anticholinergic and adrenergic drugs) and chemotherapy 
  • Withdrawal of or noncompliance with antithyroid medications
  • Diabetic ketoacidosis 
  • Direct trauma to the thyroid gland
  • Vigorous palpation of an enlarged thyroid
  • Toxemia of pregnancy 
  • Molar pregnancy
  • A family history of thyroid disease, especially Graves’ disease
  • Female gender
  • Age older than 60 years
  • Certain autoimmune diseases include type I diabetes, pernicious anemia, and Addison’s disease
  • Serum thyroid hormone levels
  • Diagnosis of precipitating factors, such as infection or other causes
  • Echocardiogram
  • Cardiac enzymes to rule out acute coronary syndromes
  • Blood test
  • Physical examination
  • Thyroid hormone levels
  • Imaging tests (thyroid scan, ultrasound and radioactive iodine uptake test)
  • Acute, life-threatening emergency
  • Fatal if left untreated
  • Good
  • Treatable
  • Cardiac arrhythmia
  • Congestive heart failure
  • Hyperthermia
  • Multiple organ failure
  • Heart issues atrial fibrillation, stroke, and congestive heart failure
  • Osteoporosis
  • Graves' eye disease
  • Thyroid storm (thyrotoxic crisis)
Medical emergency Always yes Not necessarily
Mortality rates High Low

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Medically Reviewed on 7/8/2022
Image Source: iStock image

Cleveland Clinic. Thyrotoxicosis.

Carroll R, Matfin G. Endocrine and metabolic emergencies: thyroid storm. Ther Adv Endocrinol Metab. 2010;1(3):139-145.

Misra M. Thyroid Storm. Medscape.