Myxedema Coma: Symptoms & Signs

Medically Reviewed on 11/19/2021

Myxedema coma is a severe, life-threatening complication of hypothyroidism. Before an individual develops myxedema coma, signs and symptoms characteristic of hypothyroidism are present for a long time, and the condition may have gone undiagnosed, or the hypothyroidism may have not been treated properly.

Symptoms and signs of myxedema coma include

  • weakness or lethargy,
  • confusion or non-responsiveness,
  • feeling cold,
  • low body temperature, and
  • swelling of the body, especially the face, tongue, and lower legs.

Other associated symptoms and signs can include

Ultimately, the condition can lead to coma and death.

Cause of Myxedema Coma

Longstanding low levels of thyroid hormones can cause myxedema coma.

Other myxedema coma symptoms and signs

  • Confusion or Non-Responsiveness
  • Difficulty Breathing
  • Feeling Cold
  • Fluid Buildup Around the Lungs and Heart (Pleural and Pericardial Effusions)
  • Hallucinations
  • Low Body Temperature
  • Reduced Function of the Digestive System
  • Seizures
  • Slowed Heart Rate
  • Swelling of the Body, Especially the Face, Tongue, and Lower Legs
  • Weakness or Lethargy


Where is the thyroid gland located? See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.