Which lab pattern is most consistent with primary hypothyroidism?

Prepare for the Diabetes and Thyroid Disorders Test. Study with tailored quizzes and explanations, ensuring comprehensive understanding of symptoms, pathophysiology, and management practices. Ready yourself for success!

Multiple Choice

Which lab pattern is most consistent with primary hypothyroidism?

Explanation:
In primary hypothyroidism the thyroid gland isn’t making enough thyroid hormones (T3 and T4). When these hormones are low, the pituitary senses the drop and increases TSH to try to stimulate the thyroid. So the characteristic lab pattern is low T3 and T4 with a high TSH. The other patterns don’t fit because: - High T3/T4 with high TSH is unusual for a primary thyroid problem and would not reflect failing thyroid hormone production. - Normal T3/T4 with normal TSH indicates a euthyroid state. - Low T3 with high T4 but normal TSH is inconsistent—high T4 would typically suppress TSH, not leave it normal.

In primary hypothyroidism the thyroid gland isn’t making enough thyroid hormones (T3 and T4). When these hormones are low, the pituitary senses the drop and increases TSH to try to stimulate the thyroid. So the characteristic lab pattern is low T3 and T4 with a high TSH.

The other patterns don’t fit because:

  • High T3/T4 with high TSH is unusual for a primary thyroid problem and would not reflect failing thyroid hormone production.

  • Normal T3/T4 with normal TSH indicates a euthyroid state.

  • Low T3 with high T4 but normal TSH is inconsistent—high T4 would typically suppress TSH, not leave it normal.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy