In simple words: Myxedema coma is a serious medical emergency caused by severely low thyroid hormone levels over a long period. It can cause loss of consciousness, low body temperature, and problems with breathing, heart function, and other organs. It's often triggered by another illness like an infection or heart problems in people who already have low thyroid function.

Myxedema coma, also known as myxedema crisis, is a rare and life-threatening complication of severe, longstanding hypothyroidism. It represents a decompensated state where the body's normal compensatory mechanisms fail, often triggered by factors such as infection, heart failure, stroke, or certain medications.It is characterized by altered mental status, hypothermia, and multiple organ system dysfunction. While the term includes "coma," patients may present with varying degrees of consciousness, ranging from confusion to deep unconsciousness.

Example 1: A 70-year-old woman with a history of undiagnosed hypothyroidism presents to the emergency department with altered mental status, hypothermia, and difficulty breathing after developing pneumonia., A 55-year-old man with a history of thyroidectomy presents with decreased consciousness, low blood pressure, and bradycardia during a cold winter spell., A 60-year-old woman with long-standing, treated hypothyroidism experiences a stroke and subsequently develops myxedema coma due to the physiological stress.

Documentation should include evidence of severe hypothyroidism (low T3/T4, high TSH), altered mental status (e.g., Glasgow Coma Scale), hypothermia, and any precipitating factors (e.g., infection, heart failure). Other relevant lab results, such as electrolyte imbalances and arterial blood gases, should also be documented.

** The code E03.5 does not specify the underlying cause of hypothyroidism or any comorbidities.It is crucial to document and code these separately.