TSH (Thyroid Stimulating Hormone)

CPT: 84443



Expected Turnaround Time

24 Hours

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements


Serum, Plasma


SST (Serum), Red Top (Separate Serum), Lithium Heparin (Plasma)

Storage Instructions

Room Temp., Refrigerated (2-8 C)

Stability Requirements

Room temp. 72hrs, Refrigerated 7 days

Test Details

Additional Information

Thyroid-stimulating hormone (TSH) is also known as thyrotropin, a glycoprotein hormone produced by the anterior pituitary gland. It is the primary stimulus for thyroid hormone production by the thyroid gland and plays a crucial role in regulating thyroid function. The thyroid gland is a small, butterfly-shaped gland situated in the front of our neck. The thyroid gland produces hormones and controls various physiological processes, including metabolism, body temperature regulation, muscle strength, weight management, and mood.   

 This test measures thyroid-stimulating hormone (TSH) levels in the blood. TSH is a hormone that stimulates the thyroid gland to make other hormones such as thyroxine (T4) and triiodothyronine (T3). Metabolism, or how the body consumes and stores energy, is controlled by T3 and T4. TSH is produced by the pituitary gland and acts on the thyroid gland by attaching to the TSH receptor. The pituitary gland is also called the “master gland” since it produces various hormones that influence other glands in the body. Too low or too high T3 and T4 hormone levels are detected by the pituitary gland. It will produce TSH in response, stimulating the thyroid gland to make the right amount of hormones.

If a thyroid is underactive, the TSH levels may be elevated as the pituitary gland tries to stimulate the thyroid to generate more T3 and T4. The TSH may be abnormally low if a thyroid is overactive because the pituitary gland stops producing TSH when the thyroid hormone levels are too high. 

The TSH level checks if the thyroid gland is in proper working order. TSH is commonly assessed as part of a thyroid panel, including tests of thyroid hormones. Additional thyroid tests may be requested if TSH is checked alone, and the result is abnormal. 


TSH testing can be used for a variety of reasons, including: 

  • Determining if the thyroid gland is underactive or overactive. 
  • Screening of thyroid disease before symptoms appear, especially in newborns. 
  • Evaluation of a thyroid nodule (a lump on the thyroid gland).  
  • Evaluation of goiter (enlargement of the thyroid gland).  
  • Diagnosis of thyroid-related diseases such as Hashimoto’s thyroiditis, Graves’ disease, and thyroid cancer. 
  • Monitoring a patient’s response to treatment for hypothyroidism, hyperthyroidism, or another thyroid condition. 




  1. Pirahanchi Y, Toro F, Jialal I. Physiology, Thyroid Stimulating Hormone. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499850/  
  2. Cooper DS. Thyroid hormone treatment: New insights into an old therapy. JAMA. 1989; 261(18):2694-2695. PubMed 2709547  
  3. Ericsson UB, Fernlund P, Thorell JI. Evaluation of the usefulness of a sensitive immunoradiometric assay for thyroid-stimulating hormone as a first-line thyroid function test in an unselected patient population. Scand J Clin Lab Invest. 1987; 47(3):215-221. PubMed 3589485  
  4. Greenspan SL, Klibanski A, Schoenfeld D, et al. Pulsatile secretion of thyrotropin mn Man. J Clin Endocrinol Metab. 1986; 63(3):661-668. PubMed 3734036  
  5. Kelley S. Endocrinology Update: Thyroid Disorders. FP Essent. 2016 Dec; 451:11-16. PMID: 27936530.  
  6. McDermott MT. Hyperthyroidism. Ann Intern Med. 2020 Apr 7;172(7): ITC49-ITC64. doi: 10.7326/AITC202004070. PMID: 32252086.  


Statement on Medical Necessity
All ordered tests should be medically necessary for the diagnosis or detection of disease, illness, impairment, symptom, syndrome, or disorder and the results should be used in the medical management and treatment decisions for the patient. Solaris requires ICD-10 codes with each order for lab testing and both the tests ordered and the diagnosis should be documented in the provider’s medical record for the patient. The United States Department of Health and Human Services, Office of Inspector General, takes the position that a provider who orders medically unnecessary tests may be subject to civil penalties.

Panels and Profiles
Solaris offers Providers the convenience of ordering test combinations in a group at times with the flexibility to choose appropriate test(s) for individual patients. Providers should only order those tests that he or she believes are medically necessary for each patient, and a lesser inclusive profile or individual tests should be ordered if not all tests in the test combination/profile are medically necessary. All tests offered in a test combination/profile may be ordered separately as individual tests. Solaris encourages clients to contact their Solaris representative if the testing configurations shown do not meet individual needs for any reason, or if some other combination of procedures is needed.

CPT Codes
CPT Codes listed are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are the responsibility of the billing party and are listed here for informational purposes. Correct coding may vary from one carrier to another. Solaris may bill specific carriers using codes other than what is shown.


For questions or inquiries related to testing please reach out to
customerservice@solarisdx.com or contact us by phone at (844) 550-0308.