Undetectable or Low TSH Levels
The pituitary gland stops producing TSH because the thyroid is autonomously overproducing hormones.
Description
A phlebotomist draws a venous blood sample, which is then analyzed in a laboratory using immunoassays. This clinical method originated from endocrinology research establishing the negative feedback loop between the pituitary gland and the thyroid. It remains the gold standard for initially detecting thyroid dysfunction.