What condition is characterized by altered levels of consciousness due to hypothyroidism?

Myxedema coma is a severe and life-threatening form of hypothyroidism characterized by significantly decreased metabolic rate and altered mental status. In this condition, individuals may present with profound lethargy, confusion, or even coma due to extremely low levels of thyroid hormones, which play a crucial role in regulating metabolism and energy level in the body.

Patients with myxedema coma may also exhibit other symptoms commonly associated with hypothyroidism, such as cold intolerance, dry skin, and bradycardia. The lack of thyroid hormones can lead to decreased cerebral metabolism, resulting in altered levels of consciousness. This condition requires immediate medical intervention, including the administration of thyroid hormone replacement and supportive care.

The other conditions listed do not typically lead to altered consciousness due to hypothyroidism. For instance, a thyroid storm involves a sudden increase in thyroid hormones, leading to hypermetabolism and not decreased consciousness. Proptosis is related to Graves' disease and not a direct consequence of hypothyroidism. Addison's disease is an adrenal insufficiency that can cause altered mental status, but it is unrelated to thyroid hormone levels. Thus, myxedema coma is distinctly associated with the complications of hypothyroidism and altered consciousness.