What is the recommended approach for a comprehensive Review of Systems (ROS) for a patient with suspected thyroid disorders, including evaluation of symptoms, medical history, physical examination, and laboratory tests?

Review of Systems for Thyroid Disorders

When evaluating a patient for suspected thyroid dysfunction, focus your ROS on specific symptom clusters that distinguish hypothyroidism from hyperthyroidism, recognizing that these symptoms are nonspecific and diagnosis ultimately requires biochemical confirmation with TSH testing. 1, 2

Hypothyroidism-Specific Symptoms to Assess

Constitutional and Metabolic:

• Fatigue and generalized weakness 1, 2
• Cold intolerance 1, 2
• Unintentional weight gain despite normal appetite 1, 2

Dermatologic and Hair:

• Dry skin 1, 2
• Hair loss or thinning 1

Gastrointestinal:

• Constipation 1, 2

Neuropsychiatric:

• Mental slowing or cognitive impairment 1, 2
• Depression 1
• Insomnia (in advanced cases) 1

Musculoskeletal:

• Muscle cramps 1

Voice and Throat:

• Voice changes or hoarseness 1, 2

Hyperthyroidism-Specific Symptoms to Assess

Metabolic and Constitutional:

• Unintentional weight loss 1
• Heat intolerance 1

Cardiovascular:

• Palpitations 1
• Rapid heart rate 1

Gastrointestinal:

• Diarrhea 1

Neuropsychiatric:

• Anxiety 1
• Tremors 1

Endocrine:

• Polyuria and polydipsia (if concurrent type 1 diabetes develops) 1

Critical High-Risk Features in History

Target these specific populations for aggressive case finding, as they have substantially elevated risk: 1

• Women older than 60 years 1
• Previous thyroid surgery or known thyroid dysfunction 1
• History of radiation exposure to thyroid gland (radioactive iodine or external beam radiation) 1
• Type 1 diabetes mellitus 1
• Personal history of autoimmune disease 1
• Family history of thyroid disease 1
• Atrial fibrillation 1
• Down syndrome 1, 3
• Postpartum status (within 12 months) 1, 4

Physical Examination Findings to Document

Thyroid Gland Assessment:

• Palpable thyroid abnormalities or nodules (any palpable nodule warrants TSH testing and ultrasound) 1, 5
• Diffuse goiter 6
• Thyroid tenderness (suggests thyroiditis) 1

Cardiovascular:

• Heart rate and rhythm (assess for atrial fibrillation in hyperthyroidism) 1

Neurologic:

• Assess for tremor 1
• Mental status changes (severe hypothyroidism can progress to myxedema coma) 1, 2

Laboratory Testing Algorithm

Initial screening test is TSH measurement alone: 1, 2, 7

If TSH is elevated (hypothyroidism suspected):

• Measure free T4 to distinguish subclinical from overt hypothyroidism 1, 2
• Consider thyroid peroxidase (TPO) antibody testing 1

If TSH is low or suppressed (hyperthyroidism suspected):

• Measure free T4 or total T3 1
• Consider thyroid stimulating hormone receptor antibody (TRAb) or thyroid stimulating immunoglobulin (TSI) to distinguish Graves' disease from thyroiditis 1
• Consider radioactive iodine uptake scan (RAIUS) or Technetium-99m scan if feasible 1

For pregnant patients with suspected hypothyroidism:

• Measure both TSH and free T4 simultaneously 1, 8
• Maintain TSH in trimester-specific reference ranges 8

Special Considerations for Specific Populations

Pregnant or postpartum women:

• Screen immediately upon pregnancy confirmation if pre-existing hypothyroidism 8
• Monitor TSH every 4 weeks during pregnancy 8
• Thyroiditis is common postpartum and typically presents 1-2 months after delivery 1, 4

Patients on immunotherapy (checkpoint inhibitors):

• Routine monitoring shows thyroid dysfunction in 6-20% of patients 1
• Hypophysitis can present with low free T4 and low/normal TSH (secondary hypothyroidism) 1
• Always start steroids before thyroid hormone replacement if both adrenal insufficiency and hypothyroidism are present to avoid adrenal crisis 1

Down syndrome patients:

• Clinical symptoms are unreliable due to overlap with Down syndrome features (slow speech, thick tongue, slow mentation) 1, 3
• Require more intensive screening than general population 3
• Use TSH >6.5 mU/L as threshold for elevated values 3

Critical Pitfalls to Avoid

• Do not rely on symptoms alone for diagnosis—signs and symptoms are nonspecific, especially early in disease, and biochemical confirmation is mandatory 2, 4
• Do not screen the general asymptomatic population—population-based screening is not recommended; instead, perform aggressive case finding in high-risk groups 1
• Do not assume fatigue or obesity indicates hypothyroidism—the vast majority of patients with these complaints do not have thyroid dysfunction 4
• Do not treat based on a single abnormal TSH—confirm abnormalities over time, as spontaneous normalization occurs frequently 1
• In Down syndrome, do not rely on clinical diagnosis—the overlap between Down syndrome features and hypothyroid symptoms makes clinical assessment unreliable 1, 3