FT4 (Thyroxine- Free)

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FT4 measures the free, biologically active thyroxine hormone in blood to assess thyroid gland function and metabolism.

₹149.00 ~~₹300.00~~

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Test Details

Also Known As

Free T4 Test, FT4 Assay, Free Thyroxine Test, Serum FT4, Thyroid T4 Free Test

Sample Type

Blood

Gender

Male, Female

Age Group

Adolescents to elderly (as advised by physician)

Pathology

Test Code

Free Thyroxine (FT4) is the unbound form of the thyroid hormone T4 that is readily available for use by body tissues. It plays a key role in regulating metabolism, growth, heart function, body temperature, and energy balance. Unlike total T4, FT4 is not affected by variations in thyroid-binding proteins, making it a more reliable indicator of true thyroid function.

The FT4 test is commonly used to diagnose and monitor thyroid disorders such as hypothyroidism and hyperthyroidism. It is especially valuable when TSH levels are abnormal or when binding protein levels are altered, such as during pregnancy, liver disease, or medication use. FT4 results are typically interpreted alongside TSH and FT3 for comprehensive thyroid evaluation.

Recommended Tests

Frequently Asked Questions

It is used to assess thyroid function and diagnose hypo- or hyperthyroidism.

FT4 measures only the active, unbound hormone, while total T4 includes both bound and free forms.

Fasting is usually not required unless advised with other tests.

High FT4 levels may indicate hyperthyroidism or excessive thyroid hormone intake.

Low FT4 levels are commonly associated with hypothyroidism.

No, it is usually tested along with TSH and FT3 for accurate thyroid assessment.

FT4 (Thyroxine- Free)