The STOP-BANG questionnaire — the most widely used OSA screening tool in hospitals worldwide. Answer 8 yes/no questions to find your risk level.
Obstructive sleep apnea (OSA) is one of the most underdiagnosed medical conditions in the world. Estimates suggest that 80–90% of people with moderate-to-severe OSA remain undiagnosed. This is partly because the primary symptoms — snoring, daytime fatigue, and non-restorative sleep — are normalized or attributed to other causes, and partly because OSA occurs during sleep when patients can't observe it themselves. A bed partner noticing apnea episodes is often the first diagnostic clue.
During an OSA episode, the muscles of the throat and tongue relax during sleep, partially or completely blocking the upper airway. Airflow stops (apnea) or reduces significantly (hypopnea) for 10 seconds or longer. As oxygen saturation drops, the brain triggers a brief arousal — not full waking, but enough to restore muscle tone and reopen the airway. The person gasps or snorts and resumes breathing, often without conscious awareness.
In moderate-to-severe OSA, these events can occur 15–30+ times per hour throughout the night. The cumulative effects are devastating: sleep is massively fragmented, deep sleep and REM are severely curtailed, oxygen saturation repeatedly drops, cortisol and adrenaline are repeatedly triggered, and the cardiovascular system is placed under chronic stress. People with untreated severe OSA have a 2–3× increased risk of hypertension, heart attack, stroke, and type 2 diabetes.
STOP-BANG was developed by Frances Chung et al. at the University of Toronto in 2008 and validated in surgical populations. It has since been validated across general population and primary care settings. It has a sensitivity of 93% for moderate-to-severe OSA at a score of 3+, making it one of the most effective simple screening tools available. STOP-BANG is now recommended by multiple anesthesiology societies for pre-operative OSA screening worldwide.
The 8 items assess the most evidence-based risk factors for OSA: snoring (the most common symptom), tiredness and daytime sleepiness, observed breathing cessation, high blood pressure (a consequence and risk factor), BMI above 35, age above 50, neck circumference above 40cm (a stronger predictor than general obesity), and male sex (men have 2–3× higher OSA prevalence than pre-menopausal women).
The major risk factors for OSA are: obesity (particularly central obesity and elevated BMI — fat deposition around the neck and upper airway narrows the lumen); male sex (hormonal differences, neck anatomy); age over 50 (muscle tone decreases, airway more collapsible); large neck circumference (>40cm/16in); craniofacial anatomy (retrognathia, large tonsils, high arched palate); alcohol and sedative use (relax airway muscles); nasal congestion (increases negative pressure during inhalation); and family history (genetic craniofacial anatomy).
Women are increasingly recognized as an underdiagnosed population — OSA in women often presents differently (more insomnia, less snoring, more fatigue and mood symptoms) and is frequently misattributed to depression or anxiety. Post-menopausal women have similar prevalence to men of the same age.
CPAP (Continuous Positive Airway Pressure) therapy eliminates apnea events by delivering pressurized air that acts as a pneumatic splint for the upper airway. For people with moderate-to-severe OSA, the benefits of consistent CPAP use are substantial: daytime sleepiness resolves; cognitive function improves; blood pressure often decreases significantly (CPAP is one of the few non-pharmacological antihypertensive interventions with good evidence); accident risk returns toward baseline; and long-term cardiovascular risk decreases. Modern CPAP machines are quiet, compact, and far more tolerable than earlier generations.