Understanding Myxedema Coma:  Causes, Symptoms, Treatment, Prognosis, and Prevention

Understanding Myxedema Coma:  Causes, Symptoms, Treatment, Prognosis, and Prevention

Understanding myxedema coma
©️ Olga Kononenko on Unsplash

Myxedema coma is a rare but life-threatening medical emergency that results from severe, untreated hypothyroidism. Also simply known as severe hypothyroidism, this condition occurs when the thyroid gland fails to produce enough thyroid hormones, leading to a range of systemic complications. Myxedema coma is characterized by a profound slowing of bodily functions, leading to a range of symptoms that, if left untreated, can be fatal.

In this article, we will delve into the details of myxedema coma, including its causes, symptoms, diagnosis, treatment, prognosis, and prevention.

What causes myxedema coma?

Myxedema coma typically develops in individuals with longstanding, untreated hypothyroidism. The most common causes of hypothyroidism include:

  • Autoimmune thyroiditis: Hashimoto’s thyroiditis is an autoimmune disorder where the immune system attacks and damages cells in the thyroid gland, thereby impairing thyroid hormone production.
  • Iodine deficiency: Inadequate dietary intake of iodine can lead to hypothyroidism, especially in regions with low iodine levels in the soil and among populations with limited access to iodized salt.
  • Thyroid surgery or radiation: In cases where the thyroid gland is surgically removed or ablated due to thyroid cancer or other conditions, hypothyroidism is likely to develop.

Besides the main underlying causes of hypothyroidism, myxedema coma, in some cases can be triggered by factors such as: 

  • Medication non-compliance: Patients with hypothyroidism who do not take their prescribed thyroid hormone replacement medication as directed are at higher risk of myxedema coma.
  • Infection or illness: Serious infections or illnesses, such as pneumonia, urinary tract infections and sepsis, can trigger myxedema coma, particularly in individuals with underlying hypothyroidism. 
  • Cold weather: Exposure to cold temperatures can be a contributing factor, as it can slow down metabolic processes in individuals with hypothyroidism.
  • Medications: Certain medications, like lithium, amiodarone, and sedatives, are capable of triggering myxedema coma, especially in individuals with untreated hypothyroidism. Sedative drugs in particular can contribute to myxedema coma by suppressing the central nervous system.

What are some symptoms of myxedema coma?

Myxedema coma is characterized by a constellation of severe symptoms. These symptoms can be more subtle at first (when hypothyroidism is relatively mild) but progress rapidly as the condition worsens. Symptoms of myxedema coma include:

  • Lethargy and fatigue: Individuals with myxedema coma may appear extremely tired and have difficulty staying awake.
  • Hypothermia: A dangerously low body temperature, often below 95°F (35°C), is a  hallmark of myxedema coma. This can lead to shivering, cold extremities (hands and feet), and even confusion.
  • Bradycardia: The heart rate slows down significantly, leading to a slow pulse and reduced cardiac output.
  • Altered mental status: This can range from confusion and disorientation to severe stupor. In severe cases, patients may eventually slip into a coma, which is a life-threatening state of unconsciousness.
  • Respiratory distress: Breathing becomes shallow, and in severe cases, individuals may experience respiratory failure.
  • Hypotension: Blood pressure drops to dangerously low levels.
  • Myxedema and swelling: The term “myxedema” refers to the accumulation of mucopolysaccharides (also called glycosaminoglycans) in the skin, leading to puffiness, particularly around the eyes and face. Mucopolysaccharides are sugar molecules present in the mucus and fluids that lubricate the joints.
  • Gastrointestinal issues (such as constipation with fecal retention and abdominal pains)

It cannot be overemphasized that early recognition of these symptoms is crucial for prompt intervention.

How is myxedema coma diagnosed?

Usually, symptoms help give an indication of the manifestation of myxedema coma. However, diagnosing myxedema coma involves a combination of clinical evaluation and laboratory tests, and is not solely based on the presence of symptoms. The following approaches are useful in making the diagnosis:

  • Physical examination: The patient’s vital signs, skin appearance, and mental status are assessed by the doctor.
  • Blood tests: Thyroid function tests, including measurements of TSH (thyroid-stimulating hormone) and thyroid hormones (T3 and T4), help confirm hypothyroidism. Abnormally low levels of T4 with abnormally high levels of TSH are typical of myxedema coma. Since this condition is considered a medical emergency, the TSH and T4 levels of the individual should be checked immediately myxedema coma is suspected.
  • Additional tests: Other tests, such as electrolyte panels and imaging studies, may be performed to identify underlying causes and complications. A complete blood count and an arterial blood gas analysis may also be required to assess the severity of associated complications.

How is myxedema coma treated?

In order to ensure effective treatment, addressing the root cause of hypothyroidism is crucial, whether it is autoimmune, iodine deficiency, or medication-induced. In any case, myxedema coma requires immediate hospitalization and treatment in order to stabilize the patient while addressing the underlying thyroid dysfunction. Treatment strategies for myxedema coma include:

  • Thyroid hormone replacement: Intravenous (IV) administration of synthetic thyroid hormones, such as levothyroxine and sometimes liothyronine, is crucial to rapidly raise thyroid hormone levels and restore thyroid function.
  • Supportive care: Patients may require respiratory support, IV fluids, warming measures to raise body temperature, and medications to manage symptoms like bradycardia and hypotension. In severe cases of respiratory failure, mechanical ventilation may be needed.
  • Corticosteroids: In some cases, corticosteroids like hydrocortisone may be given to reduce inflammation and to avert the possibility of secondary hypothyroidism.

Prognosis and Recovery

Generally, the prognosis of myxedema coma is not very good. However, with prompt and appropriate treatment, patients with myxedema coma can recover, although it may take several weeks to return to normal thyroid function. The prognosis depends on several factors, including the severity of the condition, any underlying health issues, and the timeliness of treatment. Delayed treatment can lead to severe complications, including multi-organ failure and mortality. Close monitoring, ongoing thyroid hormone replacement, and addressing the root cause of hypothyroidism are essential for long-term management.

Can myxedema coma be prevented?

The best way to prevent myxedema coma is by managing hypothyroidism effectively to ensure that it does not worsen. This involves:

  • Regular thyroid monitoring: It is extremely important to work closely with your healthcare provider to monitor your thyroid hormone levels. Regular blood tests can help ensure that your thyroid hormone levels are within the reference range.
  • Medication compliance: If you have been prescribed thyroid hormone replacement therapy (e.g., levothyroxine), it is essential to take your medication as directed by your healthcare provider. Missing doses or discontinuing treatment can lead to uncontrolled hypothyroidism. Do you have trouble remembering to take your daily dose on time? Worry no more! The ThyForLife app’s got you covered. Download the app today to set automated reminders for your medication intake.
  • Regular follow-up appointments: Attend regular follow-up appointments with your healthcare provider. They can adjust your medication as and when needed, based on your thyroid hormone levels and overall health.
  • Staying informed: Educate yourself on the signs and symptoms of myxedema coma, as well as the warning signs of worsening hypothyroidism. Early recognition of these symptoms can lead to quicker medical intervention.
  • Seeking prompt medical care: If you suspect that you or someone you know is experiencing symptoms of myxedema coma, seek immediate medical attention. Time is of the essence as far as the treatment of this condition is concerned.

Key Takeaways:

  • Myxedema coma is a rare but potentially life-threatening complication of severe hyperthyroidism. 
  • Understanding the symptoms, causes, and treatment options for myxedema coma is essential for healthcare professionals and individuals at risk to ensure timely and appropriate care.
  • A distinctive symptom of myxedema coma is the accumulation of mucopolysaccharides in the skin, resulting in facial puffiness and swelling.
  • The most common causes of hypothyroidism include autoimmune thyroiditis (Hashimoto’s disease), thyroid surgery, radioactive iodine therapy, radiofrequency ablation, and medications that suppress thyroid function. 
  • Myxedema coma is a medical emergency that requires immediate hospitalization and treatment. 
  • The primary goals of treatment are to stabilize the patient and address the underlying thyroid dysfunction. 
  • Patients often require intensive care to manage complications such as hypothermia,\ and respiratory distress.
  • Following treatment, continuous monitoring of vital signs and response to treatment is essential.
  • With prompt and appropriate treatment, patients have a good chance of recovery. 
  • Prevention through vigilant thyroid management remains the best approach to avoid this life-threatening condition. 
  • If you suspect someone may have a myxedema coma, seek immediate medical attention to ensure the best possible outcome.


At ThyForLife, we do our utmost to provide accurate information. For detailed medical information regarding diagnosis, treatment, and general practices please consult your healthcare professional. Always listen to the advice of your healthcare provider.
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