Diagnosis of Sleep Apnea
All adults should be screened for snoring at every routine health visit, and those with habitual snoring require objective testing with polysomnography (PSG) or home sleep apnea testing (HSAT) to diagnose obstructive sleep apnea (OSA). 1
Initial Screening and Clinical Evaluation
Screening Questions at Routine Visits
- Ask specifically about snoring (the most sensitive screening measure), witnessed apneas, nocturnal choking or gasping, restlessness during sleep, and excessive daytime sleepiness at every health maintenance visit 1, 2
- Screen for associated conditions including obesity, hypertension, stroke, congestive heart failure, diabetes, and atrial fibrillation 1, 2
- High-risk populations requiring expedited evaluation include: obese patients, those with treatment-refractory hypertension, congestive heart failure, atrial fibrillation, type 2 diabetes, stroke history, nocturnal dysrhythmias, pulmonary hypertension, commercial truck drivers, and bariatric surgery candidates 2
Comprehensive Sleep History
Before any diagnostic testing, obtain a detailed sleep history evaluating: 2, 1
- Snoring patterns and witnessed breathing interruptions
- Gasping/choking episodes during sleep
- Excessive daytime sleepiness (quantify with Epworth Sleepiness Scale)
- Total sleep duration and sleep quality
- Nocturia, morning headaches, sleep fragmentation
- Decreased concentration, memory problems, and decreased libido
- Nonrefreshing sleep and irritability
Physical Examination Findings
Focus on features suggesting increased OSA risk: 2
- Neck circumference >17 inches (men) or >16 inches (women)
- Body mass index >30 kg/m²
- Modified Mallampati score of 3 or 4
- Retrognathia, macroglossia, tonsillar hypertrophy
- Elongated/enlarged uvula, high-arched or narrow hard palate
- Nasal abnormalities (polyps, septal deviation, turbinate hypertrophy)
- Cardiovascular, respiratory, and neurologic system abnormalities
Diagnostic Testing Algorithm
Clinical Tools Cannot Replace Objective Testing
Questionnaires, clinical prediction algorithms, and screening tools alone cannot diagnose OSA and must not be used without PSG or HSAT. 2, 1 Self-reported symptoms are unreliable, and objective testing is always required 1
Choice of Diagnostic Test
Use PSG or HSAT for Uncomplicated Patients
For uncomplicated adult patients with suspected moderate-to-severe OSA, either in-laboratory PSG or HSAT with a technically adequate device is recommended. 2, 1 This applies to patients without significant comorbidities who have a high pretest probability of OSA 2
PSG is Mandatory for Complex Patients
PSG (not HSAT) must be used for patients with: 2, 1
- Significant cardiorespiratory disease (congestive heart failure, coronary artery disease, pulmonary hypertension)
- Potential respiratory muscle weakness from neuromuscular conditions
- Awake hypoventilation or suspected sleep-related hypoventilation
- Chronic opioid medication use
- History of stroke or transient ischemic attacks
- Severe insomnia
- Suspected comorbid sleep disorders (central sleep apnea, narcolepsy, periodic limb movements)
When Initial Testing is Inadequate
If a single HSAT is negative, inconclusive, or technically inadequate, PSG must be performed. 2 This is a strong recommendation because HSAT can miss OSA in some patients 2
If initial PSG is negative but clinical suspicion remains high, consider a second PSG. 2 This is particularly important given night-to-night variability in OSA severity 2
Split-Night Protocol Option
For efficiency, a split-night protocol (diagnostic study followed by CPAP titration in the same night) may be used instead of full-night diagnostic PSG when clinically appropriate, though this is a weaker recommendation 2
Diagnostic Criteria
OSA is diagnosed when either: 1
- ≥5 obstructive respiratory events per hour (apneas, hypopneas, or respiratory effort-related arousals) PLUS symptoms (daytime sleepiness, snoring, witnessed apneas, or awakenings with gasping/choking)
- ≥15 obstructive respiratory events per hour even without symptoms (due to increased cardiovascular disease risk)
Severity classification based on apnea-hypopnea index (AHI): 3
- Mild: AHI 5-14/hour with no or mild symptoms
- Moderate: AHI 15-30/hour with occasional daytime sleepiness
- Severe: AHI >30/hour with frequent daytime sleepiness interfering with daily activities
Critical Pitfalls to Avoid
Do not rely on the absence of daytime sleepiness to rule out OSA—many patients with severe OSA do not report sleepiness. 1 This is a common and dangerous mistake that leads to missed diagnoses 1
Do not assume all apneas are obstructive. 4 Central sleep apnea (CSA) shows absence of respiratory effort during apneic events, while OSA shows continued respiratory effort 4. This distinction is critical because treatment differs fundamentally—adaptive servo-ventilation is contraindicated in heart failure patients with reduced ejection fraction and CSA due to increased mortality risk 4
Do not skip comprehensive sleep evaluation before testing. 2 Testing should occur within a structured clinical pathway supervised by a board-certified sleep medicine physician, with appropriate follow-up to ensure findings are interpreted correctly and treatment is initiated appropriately 2
Do not use HSAT in patients with major comorbidities. 2 This includes moderate-to-severe pulmonary disease, neuromuscular disease, congestive heart failure, or suspected comorbid sleep disorders, as HSAT may miss or underestimate disease severity in these populations 2