Thyroid-Stimulating Hormone (TSH) Beta Subunit, Serum/Plasma — Mass Concentration
Measures the beta-subunit portion of thyroid-stimulating hormone in blood. This specialized test may help evaluate thyroid stimulation when other thyroid tests are unclear.
["TSH beta subunit testing provides additional information about thyroid stimulation and is usually interpreted with other thyroid and pituitary tests."]
Key facts at a glance
- LOINC
- 13897-4
- Short code
- TSH Beta SerPl-mCnc
- Synonyms
- TSH Beta SerPl-mCnc
- Category
- kidney
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.4
- Ref high
- 4
- Critical range
- 0.1 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84443
- SNOMED
- 301343003
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This blood test measures the beta-subunit portion of thyroid-stimulating hormone (TSH), a pituitary hormone that signals the thyroid gland to produce thyroid hormones. It is a specialized test and is not the same as a routine TSH test.
Why might I need this test?
A clinician may order this test when they need a more detailed evaluation of TSH production or when results from standard thyroid tests do not clearly explain a person's symptoms.
How is the test performed?
A blood sample is collected, and the laboratory measures the amount of TSH beta subunit in the serum or plasma using a validated laboratory method.
How do I prepare for the test?
No special preparation is usually required. Follow any instructions from your clinician or laboratory, and tell the healthcare team if you are taking thyroid, pituitary, or other medicines that could affect the results.
Reference range
Adult: 0.4-4.0 mIU/LN/A
Take your thyroid medication after the blood draw if applicable. No fasting required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated or reduced TSH beta-subunit level may occur with conditions affecting the thyroid or pituitary gland. Because interpretation can depend on the assay and the person's clinical situation, an abnormal result does not by itself establish a diagnosis.
Results are generally reviewed alongside TSH, free T4, other thyroid tests, symptoms, and medical history. A qualified clinician should interpret the result in context.
Short name
TSH Beta Subunit
Frequently asked questions
Is this the same as a standard TSH test?
Does the test require fasting?
Can TSH beta-subunit results diagnose a thyroid or pituitary disorder?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy