Physical Exam Findings of Obstructive Sleep Apnea
The physical examination in OSA should focus on identifying increased neck circumference (>17 inches in men, >16 inches in women), obesity markers, and upper airway anatomical abnormalities that predict airway collapse during sleep. 1, 2
Key Anthropometric Measurements
Neck circumference is the single most important physical measurement, with thresholds of >17 inches (43 cm) in men and >15.5-16 inches (39-41 cm) in women indicating significantly increased OSA risk 1, 2. This measurement should be taken at the level of the superior border of the cricothyroid cartilage 3. Neck circumference correlates directly with OSA severity and accounts for a substantial portion of variability in apnea-hypopnea index 3, 4.
Body mass index (BMI) >30 kg/m² is commonly present in OSA patients and should be documented 1, 5. The combination of elevated BMI with increased neck circumference substantially increases predictive value 1.
Upper Airway Anatomical Findings
Critical oropharyngeal findings include:
- Modified Mallampati score of 3 or 4 (inability to visualize soft palate) 1, 5
- Low-lying, elongated, or posteriorized soft palate 5, 4
- Enlarged or thick uvula 5, 4
- Tonsillar hypertrophy (grade 3-4) 1, 5
- Macroglossia (enlarged tongue) 5
- Voluminous lateral pharyngeal walls 4
These soft tissue abnormalities directly narrow the upper airway and predict both OSA presence and severity 4.
Craniofacial Abnormalities
Examine for skeletal features that reduce airway dimensions:
- Retrognathia or micrognathia (recessed or small jaw) 1, 5
- High arched or narrow hard palate 5
- Maxillomandibular deficiency 1
These findings are particularly important in non-obese patients with OSA 1.
Nasal Examination
Assess for nasal obstruction including:
Nasal obstruction contributes to mouth breathing and increased upper airway resistance 5, 4.
Cardiovascular and Systemic Findings
Document associated conditions that may result from OSA:
- Hypertension (present in majority of OSA patients) 1, 6
- Signs of right heart failure or cor pulmonale in severe cases 1
- Neurologic deficits if prior stroke 1
These findings help assess OSA complications and guide urgency of treatment 1, 6.
Clinical Context and Integration
Physical examination findings must be interpreted alongside clinical history including snoring, witnessed apneas, gasping/choking episodes, excessive daytime sleepiness (assessed by Epworth Sleepiness Scale), nocturia, morning headaches, and decreased concentration 1. The American Academy of Sleep Medicine emphasizes that neck circumference functions as a secondary criterion—it becomes clinically significant when combined with other risk factors rather than serving as a standalone diagnostic tool 2.
Common Pitfalls to Avoid
Do not rely on neck circumference alone—it must be integrated with symptoms, BMI, and upper airway anatomy 2. Normal neck circumference does not exclude OSA, particularly in patients with significant craniofacial abnormalities or severe symptoms 2.
Do not assume all obese patients have OSA—while obesity is strongly associated, the specific pattern of fat distribution in the neck and pharynx is more predictive than BMI alone 3, 4.
Recognize high-risk populations requiring lower threshold for evaluation: patients with congestive heart failure, atrial fibrillation, treatment-refractory hypertension, type 2 diabetes, stroke, or those being evaluated for bariatric surgery 1.