Which condition is characterized by low TSH and high T3 and T4?

Which condition is characterized by low TSH and high T3 and T4?

• A. Hashimoto Disease
• B. Chronic Thyroiditis
• C. Graves Disease
• D. DeQuervian Disease

Answer: (C)

When TSH is suppressed and T3 and T4 are elevated, the patient is experiencing hyperthyroidism with the pituitary gland reducing its stimulation in response to high circulating thyroid hormones. The most common cause of this pattern is Graves disease, an autoimmune condition where antibodies stimulate the TSH receptor on the thyroid, driving excess production of thyroid hormones. That excess hormones then feed back to the pituitary, lowering TSH levels. Hashimoto’s disease and chronic thyroiditis, in contrast, usually lead to hypothyroidism with high TSH and low T3/T4, not the low TSH/high hormone pattern. DeQuervain (subacute) thyroiditis can cause a transient thyrotoxic phase with low TSH, but it is typically painful and self-limited, not the persistent hyperthyroid state seen in Graves disease.

When TSH is suppressed and T3 and T4 are elevated, the patient is experiencing hyperthyroidism with the pituitary gland reducing its stimulation in response to high circulating thyroid hormones. The most common cause of this pattern is Graves disease, an autoimmune condition where antibodies stimulate the TSH receptor on the thyroid, driving excess production of thyroid hormones. That excess hormones then feed back to the pituitary, lowering TSH levels.

Hashimoto’s disease and chronic thyroiditis, in contrast, usually lead to hypothyroidism with high TSH and low T3/T4, not the low TSH/high hormone pattern. DeQuervain (subacute) thyroiditis can cause a transient thyrotoxic phase with low TSH, but it is typically painful and self-limited, not the persistent hyperthyroid state seen in Graves disease.