Diagnostic Tests for Thyroid Function

Question 1

What is the normal range for TSH?

Answer 1

0.5 - 6 U/dL.

Question 2

What does high and low TSH indicate?

Answer 2

High - hypothyroidism, Low - hyperthyroidism.

Question 3

What is the T3 and T4 test?

Answer 3

Test shows levels of free T3 an T4 in blood. With hyperthyroidism, the levels of one or both of these hormones in the blood are higher than normal.

Question 4

What is the Thyroid-stimulating immunoglobulin (TSI) test?

Answer 4

Also called a thyroid stimulating antibody test, measures the level of TSI in the blood. Most people with Graves’ disease have this antibody, but hyperthyroidism caused by other conditions does not.

Question 5

What is the Radioactive Iodine Uptake test?

Answer 5

It measures the amount of iodine the thyroid collects from the bloodstream. Low levels of iodine uptake might be a sign of hypothyroidism, whereas high levels could support Graves’ disease diagnosis.

Question 6

What is a Thyroid Scan?

Answer 6

It shows how and where iodine is distributed in the thyroid. The images of nodules and other possible irregularities help the provider diagnose the cause of the person’s hyperthyroidism.

Question 7

What are TSH and T4 levels in primary hypothyroidism?

Answer 7

TSH is low and T4 is high.

Question 8

What are TSH and T4 levels in secondary hypothyroidism?

Answer 8

TSH is low and T4 is low.