What is an expected lab result in a patient with hypothyroidism?

In a patient with hypothyroidism, one would expect to see decreased levels of thyroid hormones, particularly T4 (thyroxine). This condition is characterized by an underproduction of thyroid hormones due to various factors, such as autoimmune disease (like Hashimoto's thyroiditis), iodine deficiency, or issues with the pituitary gland. As a result, the thyroid gland does not secrete sufficient amounts of T4, and this reduction is a hallmark of hypothyroidism.

When T4 levels are low, the body compensates by increasing thyroid-stimulating hormone (TSH) levels from the pituitary gland. TSH is released in response to low thyroid hormone levels, signaling the thyroid to produce more hormones. Therefore, while elevated TSH levels are also associated with hypothyroidism, the main focus here is the decreased TH levels, specifically T4, which confirms the underlying issue of hormone deficiency.