Key Components of a Physical Examination for Suspected Thyroid Disorder
A comprehensive thyroid physical examination should include inspection and palpation of the thyroid gland, assessment of vital signs, and evaluation of systemic manifestations of thyroid dysfunction to guide appropriate laboratory testing and management.
Thyroid Gland Examination
Inspection
- Observe the neck for visible enlargement, asymmetry, or nodules
- Look for surgical scars indicating previous thyroid surgery
- Note any prominent blood vessels over the thyroid area
- Assess for tracheal deviation
Palpation
- Palpate the thyroid gland from behind or in front of the patient
- Ask patient to swallow during examination (helps identify the thyroid)
- Assess for:
- Size and consistency of the gland
- Presence of nodules (single or multiple)
- Tenderness
- Fixation to surrounding structures
- Cervical lymphadenopathy
Vital Signs Assessment
- Heart rate and rhythm (bradycardia in hypothyroidism, tachycardia in hyperthyroidism)
- Blood pressure (hypertension may be seen in hypothyroidism)
- Body temperature (low in hypothyroidism, elevated in severe hyperthyroidism)
Systemic Manifestations
Hypothyroidism Signs
- Skin: Coarse, dry, cool skin; myxedematous changes; puffy face 1
- Hair: Brittle, coarse hair; hair loss
- Neurological: Delayed relaxation phase of deep tendon reflexes (especially ankle reflex) 1
- Cardiovascular: Bradycardia, diastolic hypertension
- Musculoskeletal: Slow movements, muscle weakness 1
- Extremities: Peripheral edema, especially pretibial 1
Hyperthyroidism Signs
- Eyes: Exophthalmos, lid lag, lid retraction, periorbital edema (Graves' ophthalmopathy)
- Skin: Warm, moist skin; palmar erythema
- Neurological: Hyperreflexia, fine tremor
- Cardiovascular: Tachycardia, atrial fibrillation, widened pulse pressure
- Musculoskeletal: Proximal muscle weakness, tremor
- Extremities: Pretibial myxedema (in Graves' disease)
Limitations of Physical Examination
It's important to note that physical examination alone has limited diagnostic accuracy for thyroid disorders. According to research, no single physical sign can reliably discriminate between euthyroid and hypothyroid patients (positive likelihood ratios range from 1.0 to 3.88) 1. Even combinations of physical signs (coarse skin, bradycardia, and delayed ankle reflex) show only modest diagnostic accuracy (positive likelihood ratio of 3.75) 1.
Laboratory Testing
Physical examination findings should guide appropriate laboratory testing:
- TSH is the preferred initial test for suspected thyroid dysfunction (sensitivity 98%, specificity 92%) 2, 3
- If TSH is abnormal, free T4 measurement helps further narrow the diagnosis 3
- If TSH is undetectable and free T4 is normal, obtain T3 level 3
Special Considerations
High-Risk Populations
Pay particular attention to physical examination in:
- Elderly patients (higher prevalence of thyroid dysfunction) 2
- Postpartum women 2
- Patients with radiation exposure to the neck area 4
- Patients with Down syndrome (evaluating hypothyroidism is challenging as some symptoms overlap with Down syndrome features) 2
Thyroid Nodules
When nodules are detected during examination:
- Document size, consistency, mobility
- Assess for cervical lymphadenopathy
- Follow up with TSH measurement and thyroid ultrasonography 5
Pitfalls and Caveats
Limited diagnostic accuracy: Physical examination alone cannot reliably confirm or rule out thyroid dysfunction; laboratory testing is essential 1
Nonspecific symptoms: Many thyroid symptoms overlap with other conditions, especially in early disease 6
Subclinical disease: Patients with biochemical thyroid dysfunction may have minimal or no physical findings 2
Comorbidities: Other conditions (especially in elderly patients) may mask or mimic thyroid dysfunction signs
Medication effects: Some medications can affect thyroid function tests and clinical presentation 4
The physical examination provides valuable information but must be interpreted in conjunction with laboratory testing for accurate diagnosis and management of thyroid disorders.