Description
A T4 uptake blood test, also known as a thyroxine (T4) test, measures the level of T4 in your blood to help diagnose thyroid conditions:
What it measures
- The amount of thyroxine (T4), the main hormone produced by the thyroid gland, in your blood
Why it's done
- To check for thyroid problems, such as hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid)
Fasting not required.
