Acquired hypothyroidism resulting in reduced T4 levels is known as:

Myxedema is the term used to describe acquired hypothyroidism, which is characterized by reduced levels of thyroxine (T4). In this condition, the thyroid gland fails to produce sufficient amounts of thyroid hormones, leading to a variety of metabolic issues. The term "myxedema" specifically refers to the severe form of hypothyroidism, which can cause symptoms such as fatigue, weight gain, cold intolerance, and myxedema coma in extreme cases.

The reduction in T4 in myxedema reflects the underlying dysfunction of the thyroid, either due to autoimmune conditions (like Hashimoto's thyroiditis), iodine deficiency, or as a consequence of surgical removal of the thyroid gland. Understanding myxedema and its implications is crucial because timely diagnosis and treatment can mitigate severe consequences and improve the quality of life for affected individuals.