Thyroid Stimulating Hormone (TSH) with High-Performance Liquid Chromatography (HPLC) and Immunoassay (IA) Method
This test measures your thyroid-stimulating hormone levels in your blood, which helps your body regulate metabolism and thyroid hormone production.
["TSH helps assess thyroid function and detect potential thyroid disorders."]
Key facts at a glance
- LOINC
- 47951-9
- Short code
- TSH 2h p LRH IV SerPl-aCnc
- Synonyms
- TSH 2h p LRH IV SerPl-aCnc
- Category
- chemistry
- 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
Why This Test Is Done
Your doctor may order this test to check for thyroid problems, such as hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid). It’s often used as part of routine check-ups, especially if you have symptoms like fatigue, weight changes, or unexplained goiter (enlarged thyroid).
What to Expect Before the Test
No special preparation is needed for this blood test. You may have fasting instructions depending on your clinic, but generally, you can eat and drink normally. A healthcare provider will draw blood from a vein in your arm.
What the Test Results Mean
TSH levels can vary based on thyroid health. High levels may indicate hypothyroidism, while low levels may suggest hyperthyroidism or other conditions. Your doctor will interpret results in relation to your symptoms and medical history.
Common Conditions This Test Helps Diagnose
This test is critical for diagnosing thyroid disorders, including primary hypothyroidism (Hashimoto’s disease), primary hyperthyroidism, pituitary thyroid dysfunction, and thyroid cancer screening in some cases.
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.
TSH is a key marker for thyroid function. Abnormal levels can signal underlying issues that require medical attention, such as thyroid nodules, autoimmune thyroiditis, or pituitary gland disorders. Regular monitoring of TSH helps manage long-term thyroid conditions and prevents complications like heart problems or infertility.
Short name
TSH (Serum) with HPLC/IA
Frequently asked questions
What does an abnormal TSH result mean?
Can diet affect TSH test results?
How often should I get a TSH test?
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