# STOP-Bang: What Your Score Means

How STOP-Bang screens for obstructive sleep apnea, what each risk band means (including the rule for scores of 3 or 4), its accuracy, and what to do next.

Source: https://cpapclarity.com/learn/stop-bang-questionnaire-guide
Published: 2026-04-12
Updated: 2026-10-11
Author: Brian C.

Informational, not medical advice. Talk to your sleep physician before changing your therapy, pressure, mask, or medications.

## What Is the STOP-BANG Questionnaire?

The STOP-BANG questionnaire is a validated screening tool for obstructive sleep apnea (OSA). It was developed by Dr. Frances Chung and colleagues at the University Health Network in Toronto and published in 2008 in *Anesthesiology*. The original purpose was to give anesthesiologists a fast, reliable way to identify surgical patients at risk for OSA before they go under general anesthesia, because undiagnosed sleep apnea significantly increases the risk of airway complications during and after surgery.

Since then, the STOP-BANG has become one of the most widely used OSA screening tools in the world. It has been validated in many studies across surgical and sleep clinic populations. Its strength is simplicity: eight yes/no questions that take under two minutes to complete.

It is not a diagnosis. No questionnaire can replace a polysomnogram or [home sleep test](https://cpapclarity.com/learn/home-sleep-test-guide). But as a triage tool, it helps identify people who should be evaluated for sleep apnea. A low score lowers the odds; it does not rule OSA out. Already have a total? [Enter it on our STOP-Bang score page](https://cpapclarity.com/tools/stop-bang) to see its band. The questionnaire belongs to University Health Network, so CPAP Clarity explains scores rather than reprinting it; for a free risk score you can work out here, try the [NoSAS score](https://cpapclarity.com/tools/nosas-score).

## What STOP-BANG Stands For

Each letter in STOP-BANG stands for one yes-or-no factor. The first four (STOP) are symptoms. The last four (BANG) are measurable physical and demographic characteristics. We describe each factor in our own words below; the official wording is on the questionnaire's website.

### S: Snoring

This factor is loud, habitual snoring. It is one of the most common presentations of obstructive sleep apnea. The sound is produced by partial airway collapse during sleep. Not everyone who snores has sleep apnea, but nearly everyone with OSA snores. For more context, see our guide on [why snoring matters](https://cpapclarity.com/learn/why-snoring-shouldnt-be-ignored).

### T: Tired

This factor is daytime tiredness or sleepiness. Repeated airway obstructions fragment your sleep architecture, preventing you from reaching or sustaining the deeper stages of sleep that restore energy. The result is daytime fatigue that does not improve with more hours in bed. If sleepiness is your primary concern, the Epworth Sleepiness Scale quantifies it in more detail; our [Epworth score page](https://cpapclarity.com/tools/epworth-sleepiness-scale) explains a total your doctor gives you.

### O: Observed

This factor is breathing pauses, choking or gasping that someone else has seen while you sleep. Witnessed apneas are one of the strongest clinical indicators of OSA. Most people with sleep apnea are unaware of their breathing pauses. A bed partner's observations are often the first clue. If you sleep alone, this factor may be difficult to judge, which is a known limitation of the tool.

### P: Pressure

This factor counts high blood pressure, treated or not. The relationship between OSA and hypertension is bidirectional. Untreated sleep apnea contributes to sustained elevated blood pressure through repeated sympathetic nervous system activation during apnea events. Conversely, hypertension is an independent risk factor for having OSA. The American Heart Association recognizes OSA as a secondary cause of resistant hypertension.

### B: BMI

This factor is a body mass index (BMI) over 35. Excess adipose tissue around the upper airway narrows the pharyngeal space and increases the mechanical load on the airway during sleep. A BMI over 35 (Class II obesity) substantially increases the likelihood of OSA. If you do not know your BMI, the [NoSAS calculator](https://cpapclarity.com/tools/nosas-score) works it out from your height and weight.

### A: Age

This factor is being over 50. OSA prevalence increases with age. The pharyngeal muscles that keep the airway open during sleep lose tone over time. The Wisconsin Sleep Cohort Study (Young et al., 1993, *New England Journal of Medicine*) measured sleep-disordered breathing in adults aged 30 to 60 and reported prevalence by age and sex.

### N: Neck

This factor is a neck size of 16 inches (40 cm) or more, the single cutoff on the official STOP-Bang form from University Health Network, used for everyone. A larger neck correlates with more soft tissue around the airway, increasing the likelihood of collapse during sleep. It is one of the physical measurements most associated with OSA risk, and it overlaps with BMI rather than standing apart from it.

### G: Gender

This factor is male sex. Males are approximately two to three times more likely to have OSA than females in most studied populations (Young et al., 1993). This disparity narrows after menopause, suggesting hormonal factors play a protective role. The STOP-BANG's inclusion of gender as a risk factor reflects this well-established epidemiological finding, though it means the tool may underestimate risk in postmenopausal women. For more on this topic, see our article on [sleep apnea in women](https://cpapclarity.com/learn/sleep-apnea-in-women).

## How the STOP-BANG Is Scored

Scoring starts simple: count the number of "yes" answers out of eight.

| Score | Risk Level | Interpretation |
|-------|-----------|----------------|
| 0-2 | Low risk | OSA is less likely, though not ruled out |
| 3-4 | Intermediate risk | OSA is possible; worth discussing with your doctor |
| 5-8 | High risk | OSA is more likely; worth discussing a sleep study with your doctor |

There is one extra rule for high risk. The official STOP-Bang site (stopbang.ca, University Health Network) also counts yes to 2 or more of the first four questions (S, T, O, P) together with male sex, a BMI over 35, or a neck of 16 inches (40 cm) or larger as high risk, even when the total is only 3 or 4. The original 2008 study used a total of 3 or more as its cutoff; the 5-8 high-risk tier came from the same group's 2012 follow-up (Chung et al., *British Journal of Anaesthesia*), and the STOP-plus rule from their 2014 work on alternative scoring models (Chung et al., *Journal of Clinical Sleep Medicine*). Our [STOP-Bang score page](https://cpapclarity.com/tools/stop-bang) applies the full rule: for a total of 3 or 4 it asks how many of the first four factors were yes, and about sex, BMI and neck size.

## How Accurate Is the STOP-BANG?

The STOP-BANG has been extensively validated. Key findings from the literature:

**For moderate to severe OSA (AHI >= 15):**
- Sensitivity: about 93% for the full eight-item score in the original validation (Chung et al., 2008, *Anesthesiology*)
- A later meta-analysis reported 94% sensitivity for moderate to severe OSA in sleep clinic populations, with a similar pattern in surgical patients (Nagappa et al., 2015, *PLoS ONE*)

**For severe OSA (AHI >= 30):**
- Sensitivity was 100% in the original validation and 96% in the sleep clinic meta-analysis, meaning the STOP-BANG very rarely misses severe cases

**Specificity:**
- Low in the original validation: 43% at the moderate cutoff (AHI 15 or higher) and 37% at the severe cutoff (AHI 30 or higher)
- This means a meaningful number of people who score high risk do not actually have OSA (false positives)

In practical terms: the STOP-BANG is designed to cast a wide net. It catches most true cases, and nearly all severe ones, at the cost of flagging some people who turn out to be fine. Screening tools are built to err toward further testing rather than reassurance.

The tool performs best in populations with higher baseline OSA prevalence (surgical patients, sleep clinic referrals). In lower-prevalence general populations, the false positive rate is higher.

## STOP-BANG vs. Berlin vs. Epworth

Three screening tools come up most often in sleep apnea evaluation. Each one measures something different.

| Feature | STOP-BANG | Berlin Questionnaire | Epworth Sleepiness Scale |
|---------|-----------|---------------------|--------------------------|
| **Questions** | 8 yes/no items | 10 across 3 categories | 8 situation-based ratings |
| **Focus** | Binary risk factors | Symptom frequency patterns | Daytime sleepiness only |
| **Scoring** | Count-based (5+, or 2+ STOP answers plus male sex, BMI over 35 or large neck = high risk) | Category-based (2+ positive = high risk) | Sum (0-24, >10 = excessive sleepiness) |
| **Sensitivity** | ~93% (moderate-severe OSA) | ~86% (any sleep-disordered breathing, RDI over 5) | Not designed to detect OSA directly |
| **Best for** | Quick screening in any setting | Primary care screening with frequency data | Quantifying subjective sleepiness |
| **Developed** | Chung et al., 2008 | Netzer et al., 1999 | Johns, 1991 |
| **On this site** | [Score explained](https://cpapclarity.com/tools/stop-bang) | [Full questionnaire](https://cpapclarity.com/tools/berlin-questionnaire) | [Score explained](https://cpapclarity.com/tools/epworth-sleepiness-scale) |

The STOP-BANG is the fastest of the three. The [Berlin Questionnaire](https://cpapclarity.com/learn/berlin-questionnaire-guide) captures symptom frequency (how often you snore, how often you feel tired) which the STOP-BANG does not. The [Epworth Sleepiness Scale](https://cpapclarity.com/learn/understanding-epworth-sleepiness-scale) measures daytime sleepiness specifically and is not an OSA screener.

**Using more than one tool gives a clearer picture.** If STOP-BANG, Berlin, and Epworth all point in the same direction, the signal is strong. If results are mixed, that information is still valuable for your doctor.

## What to Do With Your STOP-Bang Result

### If Your Result Is High Risk

A high-risk STOP-BANG score is a strong signal. The next step is to talk to your doctor about a sleep study. In most cases, that means a [home sleep test](https://cpapclarity.com/learn/home-sleep-test-guide): a single-night recording done in your own bed that measures airflow, respiratory effort, and oxygen saturation. Our [diagnosis process guide](https://cpapclarity.com/learn/how-to-get-tested-for-sleep-apnea) covers what to expect from start to finish.

Consider also taking the [Berlin Questionnaire](https://cpapclarity.com/tools/berlin-questionnaire) or working out your [NoSAS score](https://cpapclarity.com/tools/nosas-score) before your appointment. Walking in with more than one screening result gives your provider a fuller starting point.

### If Your Score Is 3-4 (Intermediate Risk)

An intermediate score means you have some risk factors but the picture is not conclusive. If you have specific symptoms that concern you (loud snoring, witnessed breathing pauses, waking up gasping, persistent morning headaches), mention them to your doctor even if your overall score is moderate. Our guide on [sleep apnea symptoms](https://cpapclarity.com/learn/sleep-apnea-symptoms) can help you identify what to watch for.

### If Your Score Is 0-2 (Low Risk)

A low-risk score is reassuring but not a guarantee. The STOP-BANG's limitations mean it can miss some cases, particularly in women, younger patients, and people with atypical presentations. If you have concerning symptoms, a low STOP-BANG score should not stop you from pursuing evaluation.

### If You Are Already Diagnosed and on CPAP

If you are already on therapy, screening tools are behind you. Your focus now is understanding your data and getting the most out of your therapy. [Import your CPAP data into CPAP Clarity](https://cpapclarity.com/) to track your AHI, leak rates, pressure patterns, and usage over time. Your SD card data is read in your browser and never uploaded.

## Limitations of the STOP-BANG

No screening tool is perfect. The STOP-BANG has specific known limitations:

- **Gender bias.** The inclusion of male gender as a scored item means women start with one fewer risk point. Postmenopausal women and women with polycystic ovary syndrome (PCOS) have elevated OSA risk that the tool may not adequately capture.
- **Solo sleepers.** The "Observed" question requires a witness. People who sleep alone cannot answer it reliably, which may lower their score by one point.
- **Low specificity.** The tool flags many people who do not have OSA. A high score is a reason to get tested, not a reason to assume you have the condition.
- **Not sensitive to central sleep apnea.** The STOP-BANG was designed and validated for obstructive sleep apnea. It does not screen for central sleep apnea or treatment-emergent central apnea. If central events are a concern, see our guide on [central vs. obstructive apnea](https://cpapclarity.com/learn/central-vs-obstructive-apnea).

## Reading Your Score, and Free Alternatives

If you have a STOP-Bang total, our [STOP-Bang score page](https://cpapclarity.com/tools/stop-bang) shows its band and applies the extra rule for 3 or 4. Your entries are saved in your browser so you can come back to them, and we record only the anonymous risk band to see how the page is used, never your total or answers.

If you do not have a total, two free screeners on this site give a comparable read:

1. The [NoSAS score](https://cpapclarity.com/tools/nosas-score), five facts (neck size, BMI, snoring, age and sex) scored as its authors published; see our [NoSAS guide](https://cpapclarity.com/learn/nosas-score-guide)
2. The [Berlin Questionnaire](https://cpapclarity.com/tools/berlin-questionnaire), for frequency-based risk assessment

Then bring the results to your next appointment, or use them to start the conversation about a sleep study.

*This content is for educational purposes and does not constitute medical advice. The STOP-BANG questionnaire is a screening tool, not a diagnostic instrument. Consult your physician for diagnosis and treatment decisions.*

## Primary Sources

- University Health Network. [STOP-Bang questionnaire.](http://www.stopbang.ca/osa/screening.php) The official form and scoring, with the single 16-inch (40 cm) neck cutoff. Copyright University Health Network; used here for facts and scoring only.
- Chung F, Yegneswaran B, Liao P, et al. *STOP questionnaire: a tool to screen patients for obstructive sleep apnea.* Anesthesiology. 2008;108(5):812-21. The original STOP-Bang validation; for the eight-item STOP-Bang score, sensitivity was 92.9% and specificity 43% at AHI over 15 (Table 7). [PubMed 18431116](https://pubmed.ncbi.nlm.nih.gov/18431116/)
- Chung F, Subramanyam R, Liao P, et al. *High STOP-Bang score indicates a high probability of obstructive sleep apnoea.* British Journal of Anaesthesia. 2012;108(5):768-75. [PubMed 22401881](https://pubmed.ncbi.nlm.nih.gov/22401881/) The source of the 5-8 high-risk tier.
- Chung F, Yang Y, Brown R, Liao P. *Alternative scoring models of STOP-bang questionnaire improve specificity to detect undiagnosed obstructive sleep apnea.* Journal of Clinical Sleep Medicine. 2014;10(9):951-8. [PubMed 25142767](https://pubmed.ncbi.nlm.nih.gov/25142767/) The 2+ STOP answers plus male sex, BMI or neck rule.
- Nagappa M, Liao P, Wong J, et al. *Validation of the STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea among Different Populations: A Systematic Review and Meta-Analysis.* PLoS ONE. 2015;10(12):e0143697. In sleep clinic populations, reports sensitivity of 90%, 94% and 96% for any, moderate-to-severe and severe OSA, with a similar trend in surgical patients. [PLoS ONE 0143697](https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0143697)
- Young T, Palta M, Dempsey J, Skatrud J, Weber S, Badr S. *The occurrence of sleep-disordered breathing among middle-aged adults.* N Engl J Med. 1993;328(17):1230-5. The Wisconsin Sleep Cohort prevalence figures behind the age and sex risk factors (24% of men vs 9% of women). [PubMed 8464434](https://pubmed.ncbi.nlm.nih.gov/8464434/)
- Chung F, Abdullah HR, Liao P. *STOP-Bang Questionnaire: A Practical Approach to Screen for Obstructive Sleep Apnea.* Chest. 2016;149(3):631-8. [PubMed 26378880](https://pubmed.ncbi.nlm.nih.gov/26378880/) The stepwise summary of the bands and the extra rule.
- Marti-Soler H, Hirotsu C, Marques-Vidal P, et al. *The NoSAS score for screening of sleep-disordered breathing: a derivation and validation study.* Lancet Respir Med. 2016;4(9):742-748. [PubMed 27321086](https://pubmed.ncbi.nlm.nih.gov/27321086/)
- Johns MW. *A new method for measuring daytime sleepiness: the Epworth sleepiness scale.* Sleep. 1991;14(6):540-5. The origin of the Epworth Sleepiness Scale used in the comparison table. [PubMed 1798888](https://pubmed.ncbi.nlm.nih.gov/1798888/)