STOP-BANG Sleep Apnea Calculator

What is the STOP-BANG questionnaire?

STOP-BANG is an eight-item obstructive sleep apnea risk screen.

Chung and colleagues developed the four-item STOP questionnaire for adults in preoperative clinics, then added body mass index, age, neck circumference, and sex to improve sensitivity. The original validation compared questionnaire results with monitored polysomnography. It was designed to identify people who may need further assessment or perioperative precautions, not to establish a diagnosis. Obstructive sleep apnea causes repeated upper-airway narrowing or collapse during sleep. Common clues include loud snoring, witnessed pauses, gasping, unrefreshing sleep, morning headache, nocturia, and daytime sleepiness. Some people have few recognized symptoms. Untreated disease can contribute to hypertension, cardiovascular risk, impaired concentration, and crashes, but the questionnaire does not measure breathing events or oxygen loss.

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The eight STOP-BANG components

Answer each item with the original threshold. Loud snoring means louder than talking or loud enough to be heard through a closed door. Tiredness refers to frequent daytime fatigue, sleepiness, or tiredness. Observed apnea means another person has seen breathing stop. Hypertension counts when diagnosed or treated, even if medication currently keeps the reading in range.

Calculate BMI from measured weight and height when possible. Measure neck circumference with a flexible tape at the level specified by the tool, keeping the tape level and not compressing tissue. The original cutoffs are BMI greater than 35 kg/m², age greater than 50 years, neck greater than 40 cm, and male sex. Values exactly at 35, 50, or 40 do not exceed those original thresholds.

Add one point for each yes. Do not change an answer to fit a desired category. If a bed partner is unavailable, mark observed apnea based on what is known rather than assuming no. Record pregnancy, prior airway surgery, current positive airway pressure treatment, sedative or opioid use, and upcoming surgery separately because they affect clinical decisions without changing the eight-point total.

For home measurement, weigh without heavy clothing and measure height without shoes before calculating BMI. Measure the neck twice with the head neutral and shoulders relaxed; repeat if the values differ. Convert inches to centimeters by multiplying by 2.54. A 16-inch neck equals 40.64 cm and therefore exceeds 40 cm. Do not estimate neck size from a dress-shirt label when a tape is available because brand sizing and preferred collar looseness vary.

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Interpreting STOP-BANG scores

The usual basic interpretation is 0 to 2 low risk, 3 to 4 intermediate risk, and 5 to 8 high risk.

In the original 177-patient validation sample, a cutoff of 3 had sensitivity of 83.6% for AHI above 5, 92.9% for AHI above 15, and 100% for AHI above 30. Specificity fell as severity increased, reaching 37% for severe disease. Those figures came from surgical patients who completed polysomnography and should not be treated as universal probabilities. High sensitivity makes a low score useful for reducing concern about moderate or severe disease in some settings, while modest specificity means many people scoring 3 or more will not have moderate or severe apnea. Prevalence changes predictive value. A sleep-clinic population, bariatric program, pregnancy cohort, and general primary-care population can produce different post-test probabilities from the same score.

Some clinical pathways refine an intermediate score by looking for at least two positive STOP items plus one of the higher-risk BANG features, but versions and thresholds vary by setting. Use the interpretation attached to the administered form. Recalculating with a modified neck or BMI threshold and calling it the original STOP-BANG score makes validation statistics inapplicable.

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Worked scoring examples

A 54-year-old man with loud snoring and treated hypertension, BMI 32, neck 39 cm, no witnessed apnea, and no daytime tiredness scores 4: snoring, pressure, age, and male sex. That is intermediate risk.

The result supports a sleep history and possible testing, especially if he has atrial fibrillation, resistant hypertension, morning headaches, or upcoming surgery. It does not show whether his AHI is 4 or 40. A 47-year-old woman with BMI 38, neck 41 cm, daytime tiredness, and witnessed pauses scores 4 despite receiving no points for age or male sex. Her observed breathing pauses and symptoms warrant evaluation. A 35-year-old man who scores 2 but has repeated gasping and a near-crash from sleepiness also needs assessment. Risk categories cannot override strong symptoms or immediate safety concerns.

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Age, sex, body size, and comorbidity

Age and male sex increase the score because they predicted risk in the original setting, but they also create blind spots. Women can have clinically important apnea at lower totals and may report insomnia, fatigue, depression, or morning headache rather than classic sleepiness. Risk often rises after menopause. Younger adults with craniofacial narrowing, enlarged tonsils, or obesity can have apnea before the age point applies.

BMI and neck size are proxies for airway risk, not requirements for disease. A lean person can have obstructive apnea, and a high BMI can raise a score without proving airway collapse. Hypertension, atrial fibrillation, heart failure, type 2 diabetes, stroke history, pulmonary hypertension, and resistant hypertension increase the clinical stakes. Chronic opioid use raises concern for central as well as obstructive events, which STOP-BANG does not distinguish.

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From screening to diagnosis

AASM recommends diagnostic testing only after a comprehensive sleep evaluation. An uncomplicated adult with signs suggesting moderate to severe obstructive sleep apnea may undergo polysomnography or a technically adequate home sleep apnea test. If a home test is negative, inconclusive, or technically inadequate while suspicion remains, polysomnography should follow. A questionnaire cannot replace either test.

Polysomnography is preferred when significant cardiorespiratory disease, possible neuromuscular respiratory weakness, awake or sleep-related hypoventilation, chronic opioid use, stroke history, or severe insomnia complicates the picture. Home tests generally use monitoring time rather than measured sleep time and may underestimate event frequency. A clinician interprets the result with symptoms, oxygen data, event type, body position, and sleep-stage information where available.

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Using STOP-BANG before surgery

Tell the surgical and anesthesia teams about a high score, a prior apnea diagnosis, current positive airway pressure settings, and any difficulty using treatment. Bring the device when instructed.

The perioperative plan may account for airway management, opioid exposure, anesthesia type, positioning, monitoring, and whether comorbid conditions are optimized. The questionnaire itself does not decide whether a procedure is safe for outpatient care. The original tool was built for surgical screening, but a positive result is not a last-minute diagnosis. When surgery is elective, the team decides whether testing or treatment should occur first. After urgent surgery, higher-risk patients may need closer respiratory monitoring. Do not start someone else's CPAP or change pressure based on a STOP-BANG score.

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Treatment after obstructive apnea is confirmed

Treatment depends on severity, symptoms, anatomy, oxygen burden, preferences, and comorbid disease. Positive airway pressure keeps the airway open and is a central option, particularly for symptomatic or moderate to severe disease. Clinicians may also use a fitted oral appliance, weight-management treatment, positional therapy, selected surgery, or combinations. Alcohol and sedatives near bedtime can worsen obstruction in some people.

A high STOP-BANG result alone is not a prescription for CPAP, an oral appliance, or weight loss. People already using treatment should not use a lower repeat score to stop it because several items are fixed and the instrument was not designed to monitor control. Follow-up uses symptoms, adherence information, device data, and repeat testing when clinically indicated.

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Limitations and urgent warning signs

STOP-BANG uses self-report and simple thresholds. It can miss disease in women, younger adults, lean adults, and people whose symptoms are not recognized. It does not assess central apnea, hypoventilation, narcolepsy, insomnia, restless legs syndrome, parasomnias, or nocturnal seizures. A score also cannot quantify oxygen loss, event duration, sleep fragmentation, or cardiovascular stress.

Arrange evaluation for loud habitual snoring with witnessed pauses, gasping, persistent sleepiness, morning headaches, or difficult-to-control blood pressure even when the score is low. Stop driving if you are fighting sleep or have had a drowsy near-crash. Call emergency services for severe breathing difficulty while awake, blue or gray color, chest pain, stroke symptoms, prolonged unresponsiveness, or an observed sleep event followed by failure to awaken normally.

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How it works

Score 0 to 8. ≥3 intermediate risk, ≥5 high risk for OSA. High scores warrant sleep study referral.

Frequently asked questions

• What is a high STOP-BANG score?≥5 indicates high probability of moderate-to-severe OSA. ≥3 suggests intermediate risk.

Related calculators

References

1. Chung et al.. STOP Questionnaire: A Tool to Screen Patients for Obstructive Sleep Apnea
2. Chung et al.. High STOP-Bang Score Indicates a High Probability of OSA
3. NIH NHLBI. Obstructive Sleep Apnea
4. Farney et al.. Validation of STOP-BANG in Patients Referred for Suspected OSA
5. Kapur et al., AASM. Diagnostic Testing for Adult Obstructive Sleep Apnea
6. Nagappa et al.. STOP-Bang Meta-analysis of Screening Performance
7. Chung et al.. Society of Anesthesia and Sleep Medicine Preoperative Guideline
8. AASM. Clinical Use of a Home Sleep Apnea Test
9. Joshi et al.. Preoperative Selection of Adults With Obstructive Sleep Apnea
10. Patil et al., AASM. Positive Airway Pressure Treatment of Adult OSA
11. Ramar et al., AASM. Oral Appliance Therapy for Obstructive Sleep Apnea