Free T3

A triiodothyronine (T3) test measures the level of T3 in a sample of your blood. It's used to help diagnose thyroid disease.

Source: MedlinePlus, U.S. National Library of Medicine

Normal range

12 published ranges, each from a named source

2.54.3 pg/mL drawn: 20 y+ · ARUP Laboratories Test Directory

19 y+: 2–4.4 pg/mL
20 y+: 2.5–4.3 pg/mL

Ranges from ARUP Laboratories Test Directory, Mayo Clinic Laboratories (Pediatric Test Catalog).

All source ranges (12)

Source	Sex	Age	Range
ARUP Laboratories Test Directory	All	≤ 3 d	2–7.9 pg/mL
ARUP Laboratories Test Directory	All	4 d – 30 d	2–5.2 pg/mL
ARUP Laboratories Test Directory	All	30 d – 2 y	1.6–6.4 pg/mL
ARUP Laboratories Test Directory	All	2 y – 6 y	2–6 pg/mL
ARUP Laboratories Test Directory	All	7 y – 11 y	2.7–5.2 pg/mL
ARUP Laboratories Test Directory	All	12 y – 19 y	2.3–5 pg/mL
ARUP Laboratories Test Directory	All	20 y+	2.5–4.3 pg/mL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	≤ 14 y	3–5.1 pg/mL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	≤ 19 y	3.3–5.3 pg/mL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	≤ 30 d	2.7–8.5 pg/mL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	≤ 1 y	3.4–5.6 pg/mL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	19 y+	2–4.4 pg/mL

What an abnormal result can be associated with

A high result: Increased circulating T4 concentration
A low result: Decreased circulating T4 concentration

Associations from LOINC2HPO (Human Phenotype Ontology). This is reference information, not a diagnosis: only a clinician can interpret your result in context.

details

Sample: Serum or plasma · LOINC
Part of: Bryan Johnson Blueprint
Monitored for: Hypothyroidism
Listed under: Hyperthyroidism · Thyroid Diseases
Code: LOINC 3051-0 · pg/mL
Also known as: Triiodothyronine (T3) Free, FT3, Free T3, T-3, T3Free

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