Chapter 45: Q45.2-4CC. (page 1008)

Lab tests of two patients, each diagnosed with excessive thyroid hormone production, revealed elevated levels of TSH in one but not the other. Was the diagnosis of one patient necessarily incorrect? Explain.

Short Answer

Expert verified

There can be two possible cases. First, the thyroid gland may produce excessive thyroid hormone despite proper hormonal input from the hypothalamus and anterior pituitary.

Second, a hyperactive thyroid gland could be caused by unusually high thyroid-stimulating hormone (TSH) levels. Thus, there is a chance for both diagnoses to be correct.

Step by step solution

Hormone

Hormones are substances generated in the body by numerous glands that serve diverse functions in the body. Hormones are required for growth and development.

Thyroid hormones

Triiodothyronine (T3) and thyroxine (T4), two thyroid hormones, are produced by the thyroid gland. Thyroid hormones regulate weight loss and growth by controlling the pace at which calories are consumed in every cell and organ of the body.

TSH (Thyroid Stimulating Hormone)

The pituitary gland that can be found at the base of brain produces TSH. TSH causes the thyroid gland to create thyroid hormones when it is stimulated. T3, T4, and TSH levels in the blood can be used to diagnose various medical issues.

Having hyperthyroidism (overactive thyroid) occurs when the thyroid gland produces too much thyroxine. In addition to weight loss, hyperthyroidism speeds up the metabolism of the body, causing a quick or irregular heartbeat.

Increased iodine levels in the body might cause the thyroid to create too many thyroid hormones.