What endocrine disorder results from a pituitary deficiency of TSH?

A deficiency of Thyroid-Stimulating Hormone (TSH), which is produced by the pituitary gland, leads to decreased stimulation of the thyroid gland. This reduction in stimulation directly impacts the production of thyroid hormones, namely thyroxine (T4) and triiodothyronine (T3). When the levels of these hormones are insufficient, the body is unable to maintain normal metabolic functions, leading to hypothyroidism.

Hypothyroidism is characterized by symptoms such as fatigue, weight gain, cold intolerance, and depression, which can manifest when the thyroid gland is not adequately stimulated to produce hormones. Since TSH is critical for the maintenance of thyroid hormone levels, a deficiency at the pituitary level results in secondary hypothyroidism, where the lack of TSH is the underlying cause of the insufficient hormonal output from the thyroid gland.

Understanding the relationship between TSH deficiency and thyroid function is essential in recognizing the pathophysiology of hypothyroidism. The other conditions listed, such as hyperthyroidism or Graves' disease, involve overproduction of thyroid hormones rather than a deficiency, and Cushing's syndrome pertains to excess cortisol production not related to TSH or thyroid function.