What does TSH reflex to t4f mean?

It makes thyroid-stimulating hormone (TSH), which tells the thyroid gland how much T4 and T3 to produce. The TSH level in your blood reveals how much T4 your pituitary gland is asking your thyroid gland to make. If your TSH levels are abnormally high, it could mean you have an underactive thyroid, or hypothyroidism.

What is a free T4 blood test for?

Free thyroxine (free T4) tests are used to help evaluate thyroid function and diagnose thyroid diseases, including hyperthyroidism and hypothyroidism, usually after discovering that the thyroid stimulating hormone (TSH) level is abnormal.

What happens if free T4 is high?

A high level of T4 indicates an overactive thyroid (hyperthyroidism). Symptoms include anxiety, unplanned weight loss, tremors, and diarrhea. Most of the T4 in your body is bound to protein. A small portion of T4 is not and this is called free T4.

What is a good range for T4 free?

The normal range for free T 4 in adults is 0.8 to 1.8 nanograms per deciliter (ng/dL). A level of free T 4 that is higher than normal could mean you have an overactive thyroid. Conditions associated with hyperthyroidism include Graves disease, an autoimmune disorder.

What does it mean if TSH reflex is high?

High TSH levels can mean your thyroid is not making enough thyroid hormones, a condition called hypothyroidism. Low TSH levels can mean your thyroid is making too much of the hormones, a condition called hyperthyroidism.

What is the difference between T4 and free T4?

T4 TESTS T4 is the main form of thyroid hormone circulating in the blood. A Total T4 measures the bound and free hormone and can change when binding proteins differ (see above). A Free T4 measures what is not bound and able to enter and affect the body tissues.

Is free T4 more important than TSH?

Free T4 travels into body tissues that use T4. Bound T4 attaches to proteins that prevent it from entering these tissues. More than 99% of T4 is bound. Because T4 is converted into another thyroid hormone called T3 (triiodothyronine), free T4 is the more important hormone to measure.