In which condition would TSH levels likely be increased?

• A. Hyperthyroidism
• B. Hypothyroidism
• C. Addison's disease
• D. Cushing's syndrome

Answer: (B)

In hypothyroidism, the thyroid gland is underactive and does not produce enough thyroid hormones (T3 and T4). In response to low levels of these hormones, the pituitary gland compensates by increasing the production of thyroid-stimulating hormone (TSH). This heightened level of TSH is an attempt to stimulate the thyroid gland to produce more thyroid hormones. Consequently, in individuals with hypothyroidism, you would expect to see elevated TSH levels as a hallmark of the condition, reflecting the body's effort to reclaim homeostasis.

In the other conditions listed, such as hyperthyroidism, TSH levels would typically be low because the excess thyroid hormones suppress TSH production. Addison's disease and Cushing's syndrome primarily affect adrenal hormone production rather than thyroid function, thus not contributing to elevated TSH levels.