TSI Blood Test


For: ,

Quest Diagnostics Test Code: 30551

This test checks for thyroid stimulating immunoglobulins (TSI) levels.

In certain instances, the body makes antibodies which can attack the thyroid gland, leading to chronic inflammation causing it to be dysfunctional. The thyroid gland is responsible for the production and release of two principal hormones called T3 and T4. TSH comes from the pituitary gland to the thyroid to stimulate the production of these hormones. It binds to a protein molecule in order to exhibit its effects. Sometimes, autoantibodies are made that bind to these proteins, switching them on. These antibodies are called thyroid stimulating immunoglobulin (TSI). When TSI is produced, it causes an increased production of T3 and T4 to be and the patient eventually becomes hyperthyroid.

This test is performed in following conditions such as:

Signs and symptoms of hyperthyroidism
• Weight loss
• Increased heart rate
• Anxiety
• Difficulty sleeping

Also Known As: Human Thyroid Stimulator (HTS), Thyroid Stimulating Antibody (TSAb), Long-acting Thyroid Stimulator (LATS), Thyretain


The Thyroid Stimulating Immunoglobulin Test (TSI Blood test) has no special requirements.


Specimen Collected
  • Blood
Estimated Time Taken

Turnaround for this test is typically 1-2 business days.