A Thyroid Function Test is a group of blood tests used to measure how well the thyroid gland is working. The thyroid is a small, butterfly-shaped gland in the neck that controls metabolism, energy production, growth, and many body functions through the release of hormones.
TFTs help diagnose thyroid disorders such as hypothyroidism, hyperthyroidism, thyroiditis, goiter, and thyroid hormone imbalance.
What is TFT
A TFT is a group of blood tests used to measure how well the thyroid gland is working. The thyroid is a small, butterfly-shaped gland in the neck that controls metabolism, energy production, growth, and many body functions through the release of hormones.
TSH (Thyroid-Stimulating Hormone)
Free T4 (Thyroxine)
Free T3 (Triiodothyronine)
Total T4 & Total T3
Thyroid Antibody Tests
Types of TFT
TSH (Thyroid-Stimulating Hormone)
What it measures:
TSH levels produced by the pituitary gland.
Purpose:
First and most important screening test
Determines thyroid overactivity or underactivity
Interpretation:
High TSH → Hypothyroidism (underactive)
Low TSH → Hyperthyroidism (overactive)
Free T4 (FT4 – Free Thyroxine)
What it measures:
The active, unbound form of the hormone T4.
Purpose:
Confirms thyroid activity level
Evaluates severity of hypo- or hyperthyroidism
Free T3 (FT3 – Free Triiodothyronine)
What it measures:
The active, unbound form of T3.
Purpose:
Evaluates hyperthyroidism
Helps detect early or mild thyroid overactivity
Total T4
What it measures:
Both bound and unbound T4 hormone.
Purpose:
Used when protein-binding abnormalities are suspected
Helpful in pregnancy, liver disease, or medication monitoring
Total T3
What it measures:
Both bound and free forms of T3.
Purpose:
Often used in diagnosing hyperthyroidism
Sometimes more sensitive in early hyperthyroidism
Thyroid Antibody Tests
These help diagnose autoimmune thyroid diseases like Hashimoto’s and Graves’.
a. TPO Antibodies (Anti-Thyroid Peroxidase)
High in Hashimoto’s and Graves’ disease
b. Thyroglobulin Antibodies (TgAb)
Seen in autoimmune thyroid disease
Used for thyroid cancer monitoring
c. TSH Receptor Antibodies (TRAb / TSI)
Confirms Graves’ disease
Predicts recurrence after treatment
Exam Duration
30 Minutes - 40 Minutes
TFT Tests Pricing
Private TFT Tests are provided on a per fee basis and are not covered by health care.
