TSI (Thyroid Stimulating Immunoglobulin)

What this laboratory test evaluates

DetailsTSI (Thyroid Stimulating Immunoglobulin) – This test is crucial for diagnosing Graves' disease, a common type of hyperthyroidism affecting about 0.4% of people in the U.S. It identifies the presence of IgG immunoglobulins, known as thyroid stimulating immunoglobulins (TSI), which are key indicators of the disease. High levels of TSI may indicate that standard antithyroid drug treatments might not be effective. Additionally, this test can predict the risk of newborns developing hyperthyroidism, as these immunoglobulins can be passed from mother to child during pregnancy.

Who might need this test?Doctors might recommend a TSI test for individuals showing symptoms of hyperthyroidism or for pregnant women with a history of thyroid issues, to assess the risk to their newborns.

Hyperthyroidism Symptoms:• Unexpected weight loss
• Rapid heartbeat
• Increased appetite
• Nervousness or anxiety
• Sweating
• Changes in menstrual patterns

What type of sample is required for this test?1 mL serum. A simple blood draw is needed.

Additional test information

This test is crucial for diagnosing Graves' disease, a common type of hyperthyroidism affecting about 0.4% of people in the U.S. It identifies the presence of IgG immunoglobulins, known as thyroid stimulating immunoglobulins (TSI), which are key indicators of the disease.

Collection and processing

• Sample type: Serum
• Fasting: No
• Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected

How Sunridge uses laboratory information

Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.

Before requesting this test

Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.