Myxedema results from?

• A. Hyperthyroidism
• B. Autoimmune thyroiditis
• C. Extreme deficiency of thyroid secretion; also known as adult hypothyroidism
• D. Excess growth hormone

Answer: (C)

Myxedema occurs when there is severe, untreated thyroid hormone deficiency in adults. When thyroid hormones are extremely low, mucopolysaccharides accumulate in the skin and other tissues, causing widespread nonpitting edema and other symptoms of low metabolism. This makes it the best description of myxedema: an extreme deficiency of thyroid secretion leading to adult hypothyroidism.

Hyperthyroidism would produce opposite effects from excess thyroid hormone, not myxedema. Excess growth hormone causes another condition (like acromegaly). Autoimmune thyroiditis can cause hypothyroidism and, over time, could lead to myxedema, but the term itself describes the severe deficiency, not a specific autoimmune cause.