Thyroxine, Free is a topic covered in the Davis's Lab & Diagnostic Tests.

To view the entire topic, please or purchase a subscription.

Nursing Central is the award-winning, complete mobile solution for nurses and students. Look up information on diseases, tests, and procedures; then consult the database with 5,000+ drugs or refer to 65,000+ dictionary terms. Explore these free sample topics:

Nursing Central

-- The first section of this topic is shown below --


Free T4, Free4.

Common Use:
A reflex test for thyroid function to assist in diagnosing hyperthyroidism and hypothyroidism in the presence of an abnormal TSH level.

Serum collected in a gold-, red-, or red/gray-top tube. Plasma collected in a green-top (heparin) tube is also acceptable.

Normal Findings:
(Method: Immunoassay)

AgeConventional UnitsSI Units (Conventional Units × 12.9)
Newborn0.8–2.8 ng/dL10–36 pmol/L
1–12 mo0.8–2 ng/dL10–26 pmol/L
1–18 yr0.8–1.7 ng/dL10–22 pmol/L
Adult–older adult0.8–1.5 ng/dL10–19 pmol/L
Pregnancy0.7–1.4 ng/dL9–18 pmol/L

-- To view the remaining sections of this topic, please or purchase a subscription --


* When formatting your citation, note that all book, journal, and database titles should be italicized* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Thyroxine, Free ID - 425190 A1 - Bladh,Mickey Lynn, AU - Van Leeuwen,Anne M, BT - Davis's Laboratory & Diagnostic Tests UR - PB - F.A. Davis Company ET - 7 DB - Nursing Central DP - Unbound Medicine ER -