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Midwest · Free T4 Levels Test – Thyroid Testing (FT4)

Free T4 Levels Test – Thyroid Testing (FT4) in Illinois

Free T4 Levels Test – Thyroid Testing (FT4) can be ordered without a referral, and this guide covers what to expect. This test measures the amount of free thyroxine (T4) in your blood to help assess thyroid function.

Typical turnaround1-3 business days
Price range$39
PreparationFollow the lab's instructions.
Sample typeBlood draw at a collection lab
ReferralNo referral required

What this test is

Free thyroxine (FT4) is a hormone produced by the thyroid gland that plays a crucial role in metabolism. This test specifically measures the unbound form of thyroxine, which is the biologically active portion available for your body's tissues to use.

What it measures

  • Free Thyroxine (FT4) — reflects the amount of active thyroid hormone available for use by the body

What the test involves

This test requires a blood sample, which is typically collected from a vein in your arm. A healthcare professional will draw the blood and place it in a collection tube.

Why it is often ordered

Clinicians often order this test to help evaluate thyroid conditions, such as an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism). It can also be used to monitor thyroid treatment.

Preparation

Follow any specific instructions provided by the laboratory before your blood draw. Some labs may ask you to fast or avoid certain medications.

How results are reported

Your results will indicate the level of free thyroxine detected in your blood sample. Reference ranges, which define what is considered typical, vary between laboratories and should be discussed with your healthcare provider.

Before you go

  • Fasting requirements
  • Medication restrictions
  • Specific preparation instructions

Cities

Free T4 Levels Test – Thyroid Testing (FT4) in Illinois communities

Choose your city for local context and to request this test.

Chicago8,595,181Free T4 Levels Test – Thyroid Testing (FT4)Rockford289,763Free T4 Levels Test – Thyroid Testing (FT4)Round Lake Beach287,012Free T4 Levels Test – Thyroid Testing (FT4)Peoria255,718Free T4 Levels Test – Thyroid Testing (FT4)Aurora183,447Free T4 Levels Test – Thyroid Testing (FT4)Springfield162,588Free T4 Levels Test – Thyroid Testing (FT4)Champaign153,278Free T4 Levels Test – Thyroid Testing (FT4)Joliet150,323Free T4 Levels Test – Thyroid Testing (FT4)Naperville149,013Free T4 Levels Test – Thyroid Testing (FT4)Bloomington134,357Free T4 Levels Test – Thyroid Testing (FT4)Elgin114,156Free T4 Levels Test – Thyroid Testing (FT4)Waukegan89,751Free T4 Levels Test – Thyroid Testing (FT4)Decatur88,002Free T4 Levels Test – Thyroid Testing (FT4)Cicero84,905Free T4 Levels Test – Thyroid Testing (FT4)Alton83,705Free T4 Levels Test – Thyroid Testing (FT4)Kankakee82,095Free T4 Levels Test – Thyroid Testing (FT4)Evanston78,454Free T4 Levels Test – Thyroid Testing (FT4)Schaumburg78,053Free T4 Levels Test – Thyroid Testing (FT4)Arlington Heights77,283Free T4 Levels Test – Thyroid Testing (FT4)Bolingbrook73,807Free T4 Levels Test – Thyroid Testing (FT4)Palatine67,754Free T4 Levels Test – Thyroid Testing (FT4)Skokie67,444Free T4 Levels Test – Thyroid Testing (FT4)DeKalb66,624Free T4 Levels Test – Thyroid Testing (FT4)Carbondale66,482Free T4 Levels Test – Thyroid Testing (FT4)Des Plaines60,413Free T4 Levels Test – Thyroid Testing (FT4)Orland Park58,622Free T4 Levels Test – Thyroid Testing (FT4)Oak Lawn58,032Free T4 Levels Test – Thyroid Testing (FT4)Berwyn56,960Free T4 Levels Test – Thyroid Testing (FT4)Mount Prospect56,510Free T4 Levels Test – Thyroid Testing (FT4)Tinley Park55,988Free T4 Levels Test – Thyroid Testing (FT4)Oak Park54,100Free T4 Levels Test – Thyroid Testing (FT4)Wheaton53,762Free T4 Levels Test – Thyroid Testing (FT4)Normal53,446Free T4 Levels Test – Thyroid Testing (FT4)Hoffman Estates52,153Free T4 Levels Test – Thyroid Testing (FT4)Downers Grove50,209Free T4 Levels Test – Thyroid Testing (FT4)Glenview48,150Free T4 Levels Test – Thyroid Testing (FT4)Elmhurst45,661Free T4 Levels Test – Thyroid Testing (FT4)Lombard44,311Free T4 Levels Test – Thyroid Testing (FT4)Plainfield44,296Free T4 Levels Test – Thyroid Testing (FT4)Buffalo Grove43,062Free T4 Levels Test – Thyroid Testing (FT4)Moline42,660Free T4 Levels Test – Thyroid Testing (FT4)Belleville42,463Free T4 Levels Test – Thyroid Testing (FT4)Bartlett41,126Free T4 Levels Test – Thyroid Testing (FT4)Romeoville40,099Free T4 Levels Test – Thyroid Testing (FT4)Crystal Lake40,082Free T4 Levels Test – Thyroid Testing (FT4)Carol Stream39,895Free T4 Levels Test – Thyroid Testing (FT4)Streamwood39,736Free T4 Levels Test – Thyroid Testing (FT4)Quincy39,687Free T4 Levels Test – Thyroid Testing (FT4)Park Ridge39,562Free T4 Levels Test – Thyroid Testing (FT4)Urbana39,189Free T4 Levels Test – Thyroid Testing (FT4)Wheeling39,104Free T4 Levels Test – Thyroid Testing (FT4)Carpentersville37,940Free T4 Levels Test – Thyroid Testing (FT4)Hanover Park37,545Free T4 Levels Test – Thyroid Testing (FT4)Rock Island37,519Free T4 Levels Test – Thyroid Testing (FT4)Calumet City36,065Free T4 Levels Test – Thyroid Testing (FT4)Addison35,999Free T4 Levels Test – Thyroid Testing (FT4)Northbrook35,108Free T4 Levels Test – Thyroid Testing (FT4)Oswego34,324Free T4 Levels Test – Thyroid Testing (FT4)Woodridge34,161Free T4 Levels Test – Thyroid Testing (FT4)Glendale Heights33,443Free T4 Levels Test – Thyroid Testing (FT4)