FT4

About This Test
Free T4 is the active thyroid hormone circulating in blood. It helps confirm if the thyroid is under‑ or over‑active, especially when TSH is abnormal.

Patient Preparation
Fasting not required.

Best Time to Test
Anytime

Tests Included
FT4

Why is it done
Symptoms such as tiredness, weight change, hair loss, or palpitations.
Investigating thyroid enlargement or nodules.
Routine screening in pregnancy or autoimmune disease.
Monitoring thyroid treatment.