What is the initial workup and treatment approach for a 55-year-old male patient with hyperthyroidism?

Initial Workup for a 55-Year-Old Male with Hyperthyroidism

The initial workup for a 55-year-old male with hyperthyroidism should include TSH, free T4, and T3 measurements, followed by tests to determine the etiology, such as TSH receptor antibodies and thyroid imaging. 1

Diagnostic Approach

Laboratory Testing

1. Initial laboratory assessment:

   • TSH and free T4 (primary screening tests)
   • Free T3 (especially helpful in symptomatic patients with minimal FT4 elevations) 2
   • Basic metabolic panel to assess for electrolyte abnormalities

2. Etiologic testing:

   • TSH receptor antibody testing if Graves' disease is suspected (especially if ophthalmopathy is present) 2
   • Thyroid peroxidase antibodies

Imaging

1. Thyroid ultrasonography:

   • Evaluates gland size, nodules, and vascularity
   • Helps differentiate between diffuse and nodular disease

2. Radioactive iodine uptake scan (RAIUS):

   • Differentiates Graves' disease (diffusely increased uptake) from toxic nodular goiter (focal increased uptake) or thyroiditis (decreased uptake) 2
   • Technetium-99m scan can be used as an alternative if recent iodinated contrast was administered

Clinical Evaluation

Key Symptoms to Assess

• Cardiovascular: Tachycardia, palpitations, atrial fibrillation (especially in older patients)
• Neuropsychiatric: Anxiety, insomnia, tremor
• Systemic: Heat intolerance, weight loss despite increased appetite, fatigue
• Gastrointestinal: Increased bowel movements or diarrhea
• Dermatologic: Warm, moist skin, excessive sweating, hair loss 1

Physical Examination Findings

• Vital signs: Tachycardia, elevated blood pressure, fever
• Thyroid: Size, tenderness, presence of nodules or bruits
• Eyes: Lid lag, exophthalmos, stare (suggestive of Graves' disease) 1
• Skin: Warm, moist skin; pretibial myxedema (in Graves' disease)
• Neuromuscular: Fine tremor, hyperreflexia

Management Approach

Immediate Symptomatic Treatment

• Beta-blockers (e.g., atenolol 25-50 mg daily or propranolol) for symptomatic relief of tachycardia, tremor, and anxiety 2
• Titrate dose to achieve heart rate <90 bpm if blood pressure allows 2

Definitive Treatment Options Based on Severity

For Mild Symptoms (Grade 1)

• Continue monitoring thyroid function every 2-3 weeks
• Beta-blockers for symptomatic relief
• For persistent thyrotoxicosis (>6 weeks), consider endocrine consultation 2

For Moderate Symptoms (Grade 2)

• Consider endocrinology consultation
• Beta-blockers for symptomatic control
• Hydration and supportive care
• Consider antithyroid medications (methimazole preferred in non-pregnant patients) 2, 3

For Severe Symptoms (Grade 3-4)

• Urgent endocrinology consultation
• Beta-blockers for symptom control
• Hospitalization may be necessary for severe cases
• Antithyroid medications (methimazole) 2, 3
• In rare cases, additional therapies including steroids, saturated solution of potassium iodide (SSKI), or surgical intervention may be needed 2

Special Considerations

Age-Related Factors

• Older adults may present with "apathetic hyperthyroidism" - minimal symptoms except for cardiovascular manifestations 1
• Atrial fibrillation may be the presenting feature in older patients
• Treatment is strongly recommended for patients ≥65 years with TSH <0.10 mIU/L 1

Diagnostic Pitfalls

• Transient thyroiditis: Can mimic Graves' disease but requires different management 2
• Central hypothyroidism: Low TSH with low FT4 suggests central hypothyroidism, not hyperthyroidism 2
• Subclinical hyperthyroidism: May still require treatment in older patients or those with cardiac risk factors 1

Follow-up Recommendations

• Monitor thyroid function every 2-3 weeks initially after diagnosis to detect potential transition to hypothyroidism, which is common after thyroiditis 2
• For patients on antithyroid medications, monitor complete blood count and liver function tests due to potential side effects 3, 4
• Once clinical evidence of hyperthyroidism resolves, a rising serum TSH indicates that a lower maintenance dose of antithyroid medication should be used 3

Complications to Monitor

• Cardiovascular: Atrial fibrillation (3-5 fold increased risk), heart failure
• Skeletal: Accelerated bone loss, increased fracture risk
• Metabolic: Weight loss, muscle wasting
• Ophthalmologic: Progressive eye disease (in Graves' disease)