What is the diagnostic workup for Graves' disease?

From the Guidelines

The diagnostic workup for Graves' disease should include a combination of clinical assessment, laboratory tests, and imaging studies, with a focus on thyroid function tests, thyroid antibody tests, and radioactive iodine uptake scan. Begin with a thorough medical history and physical examination, focusing on symptoms of hyperthyroidism and characteristic signs like exophthalmos. Laboratory tests are crucial and should include thyroid function tests: TSH (usually suppressed), free T4, and free T3 (both typically elevated) 1. Thyroid antibody tests, particularly thyroid-stimulating immunoglobulins (TSI) or thyroid-stimulating hormone receptor antibodies (TRAb), are essential for confirming the autoimmune nature of Graves' disease 1. Additional tests may include complete blood count and liver function tests. Imaging studies are also important, with radioactive iodine uptake (RAIU) scan being particularly useful in distinguishing Graves' from other causes of hyperthyroidism 1. A thyroid ultrasound can provide information about gland size and vascularity.

Key Components of the Workup

• Clinical assessment: medical history and physical examination
• Laboratory tests:
  • Thyroid function tests: TSH, free T4, and free T3
  • Thyroid antibody tests: TSI or TRAb
  • Complete blood count and liver function tests
• Imaging studies:
  • Radioactive iodine uptake (RAIU) scan
  • Thyroid ultrasound

Considerations for Referral

Physical examination findings of ophthalmopathy or thyroid bruit are diagnostic of Graves’ disease and should prompt early endocrine referral 1. If suspected, endocrine consultation is recommended for additional workup and possible medical thyroid suppression.

Prioritization of Tests

The most recent and highest quality study 1 prioritizes thyroid function tests and thyroid antibody tests in the workup for Graves' disease, with imaging studies playing a supporting role in distinguishing Graves' from other causes of hyperthyroidism.

From the Research

Diagnostic Workup for Graves' Disease

The diagnostic workup for Graves' disease involves a combination of physical examination, laboratory tests, and imaging studies. The key features of the diagnostic workup include:

• Physical examination to assess for signs of hyperthyroidism, such as diffuse goiter, ophthalmopathy, and dermopathy 2, 3, 4, 5, 6
• Laboratory tests to confirm hyperthyroidism, including:
  • Elevated levels of bound thyroxine (T4), free T4, or bound triiodothyronine 2
  • Low levels of thyroid-stimulating hormone (TSH) (< 0.1 mU/L) 2
  • Presence of serum anti-TSH-receptor antibodies (TRAbs) 3, 4
• Imaging studies, such as thyroid ultrasonography, to assess thyroid gland size and structure 4
• Thyrotropin-releasing hormone stimulation test to confirm the diagnosis when it is suspected but unclear 2

Laboratory Tests

The laboratory tests used to diagnose Graves' disease include:

• Measurement of serum T4, free T4, and triiodothyronine levels 2, 5
• Measurement of TSH levels 2, 5
• Measurement of TRAb levels 3, 4
• Thyroid function tests, such as the thyrotropin-releasing hormone stimulation test 2

Imaging Studies

Imaging studies, such as thyroid ultrasonography, may be used to:

• Assess thyroid gland size and structure 4
• Evaluate the presence of ophthalmopathy or dermopathy 3, 4