What are the diagnostic criteria and treatment options for Graves' disease?

Diagnosing Graves' Disease

Diagnose Graves' disease by confirming low TSH with elevated free T4, followed by positive TSH receptor antibody (TRAb) testing, which provides 98% sensitivity and specificity with nearly 99% diagnostic accuracy. 1, 2

Diagnostic Algorithm

Initial Laboratory Testing

• Measure TSH and free T4 (or free T4 index) as the first step to confirm thyrotoxicosis 3
• Low TSH with elevated free T4 establishes biochemical hyperthyroidism 1

Confirmatory Testing

• Order TRAb (TSH receptor antibody) testing to definitively diagnose Graves' disease 1, 2
• TRAb is the pathogenic autoantibody that stimulates the thyroid gland and is positive in Graves' disease 4, 2
• This test differentiates Graves' disease from other causes of hyperthyroidism such as toxic multinodular goiter, destructive thyroiditis, or iodine-induced hyperthyroidism 2

Physical Examination Findings

• Look for thyroid bruit on auscultation, which is diagnostic of Graves' disease 3
• Assess for ophthalmopathy including proptosis (bulging eyes), eyelid retraction, and other ocular symptoms present in 25% of patients 1, 4
• Examine for diffuse goiter, which is characteristic of Graves' disease 5, 4

Adjunctive Testing

• Thyroid ultrasonography represents one of the most important diagnostic tests alongside TRAb measurement 5
• Ultrasound shows diffuse thyroid enlargement with increased vascularity in Graves' disease 5

Clinical Context

When TRAb Testing is Particularly Critical

• Subclinical hyperthyroidism where clinical symptoms may be subtle 2
• Endocrine ophthalmopathy without overt hyperthyroidism 2
• Pregnant women to predict neonatal thyroid disease risk 2
• Differentiating autoimmune from autonomous hyperthyroidism in complex cases 2

Common Pitfalls to Avoid

• Do not rely solely on clinical symptoms, as they have poor sensitivity and specificity 2
• Do not skip TRAb testing even when the diagnosis seems clinically obvious, as it provides definitive confirmation and has prognostic value 2
• Do not confuse Graves' disease with other causes of thyrotoxicosis such as toxic multinodular goiter, which requires different management 2

Epidemiology

• Graves' disease affects approximately 3% of women and 0.5% of men during their lifetime 6
• It is the most common cause of persistent hyperthyroidism in adults 6
• The condition often occurs in young adults and has an important genetic component 7, 4