The STOP-Bang score is a simple eight-question screening tool that estimates your risk of having obstructive sleep apnea (OSA). Each question is yes or no, giving you a total score from 0 to 8. A score of 0 to 2 means low risk, 3 to 4 is intermediate, and 5 to 8 is high risk for moderate to severe sleep apnea. It was originally designed in 2008 as a quick way for anesthesiologists to flag undiagnosed sleep apnea before surgery, but it’s now widely used in primary care and sleep medicine.
What Each Letter Stands For
STOP-Bang is an acronym, with each letter representing one yes-or-no question. You get one point for each “yes.”
- S — Snoring: Do you snore loudly, enough to be heard through a closed door?
- T — Tiredness: Do you feel tired, fatigued, or sleepy during the daytime?
- O — Observed apnea: Has anyone seen you stop breathing or choke/gasp during sleep?
- P — Pressure: Do you have high blood pressure, or are you being treated for it?
- B — BMI: Is your body mass index greater than 35?
- A — Age: Are you older than 50?
- N — Neck circumference: Is your neck circumference greater than 40 cm (about 16 inches)?
- G — Gender: Are you male?
The first four items (STOP) are things you report about your symptoms and health history. The last four (BANG) are physical and demographic measurements. Neck circumference is measured at the level of the Adam’s apple area, with you standing upright.
How Risk Categories Work
A score of 0 to 2 places you in the low-risk category for moderate to severe OSA. If you score in this range, sleep apnea is unlikely to be a significant concern, though it doesn’t completely rule it out.
A score of 3 or 4 falls in the intermediate range. This is where things get less clear-cut, and further evaluation is typically needed to determine your actual risk. Your doctor may look at which specific items you scored on or consider additional factors before deciding whether to order a sleep study.
A score of 5 to 8 puts you in the high-risk category. At this level, there’s a strong chance you have moderate or severe sleep apnea that would benefit from diagnosis and treatment. In one study, 80% of people who scored 5 or higher turned out to have severe OSA when tested with overnight monitoring.
How Accurate Is It?
The STOP-Bang questionnaire is designed to cast a wide net. In its original validation, a score of 3 or higher caught 93% of people with moderate sleep apnea and 100% of those with severe sleep apnea. That high sensitivity means it rarely misses someone who truly has significant OSA.
The tradeoff is that it also flags people who don’t have sleep apnea. A score of 3 or higher has a specificity of around 63% for moderate to severe OSA, meaning roughly a third of people flagged as at-risk won’t actually have it. Raising the cutoff to 5 or higher dramatically improves specificity to about 94%, which is why that threshold is used for the high-risk category.
When researchers compared STOP-Bang scores to actual sleep study results (measured by the apnea-hypopnea index, which counts how many times per hour your breathing is disrupted), they found a strong correlation of 0.70. By contrast, the Epworth Sleepiness Scale, another common questionnaire that asks how likely you are to doze off in various situations, had a correlation of just 0.14 with sleep study results. The STOP-Bang is a far better predictor because it captures physical risk factors for airway obstruction, not just how sleepy you feel.
Accuracy Differences Between Men and Women
Because “male gender” is one of the eight scored items, men automatically start with one point, which has raised questions about fairness and accuracy. Sleep apnea has historically been underdiagnosed in women, and the built-in gender point contributes to that gap.
Research shows the tool performs somewhat differently across genders. For severe OSA, the STOP-Bang catches roughly similar proportions of men and women (about 78% and 79%, respectively). But for moderate OSA, it performs better in men. Some researchers have proposed adjusted scoring systems that use different BMI and neck circumference thresholds for men and women to improve accuracy. When the BANG portion (which includes the gender point) is added to the STOP questions, specificity actually becomes higher in women, meaning fewer false alarms in that group.
If you’re a woman who scores 2 but has symptoms like loud snoring, witnessed breathing pauses, or significant daytime fatigue, it’s still worth pursuing a sleep evaluation. The questionnaire is a screening tool, not a diagnosis.
What Happens After You Get Your Score
A STOP-Bang score doesn’t diagnose sleep apnea on its own. It tells you and your doctor whether formal testing makes sense. For high-risk scores (5 to 8), the next step is usually a sleep study, either an overnight test in a sleep lab or a home sleep apnea test that monitors your breathing, oxygen levels, and heart rate while you sleep.
For intermediate scores (3 to 4), the decision depends on the bigger picture. If your points come from the STOP items (symptoms like snoring and observed breathing pauses), that’s generally more concerning than scoring on age and gender alone. Some clinicians will proceed directly to a sleep study, while others may recommend monitoring your symptoms first.
Low scores (0 to 2) are reassuring but not a guarantee. If you have a bed partner who reports loud snoring and choking sounds, or if you wake up with headaches and feel exhausted despite getting enough hours of sleep, those symptoms are worth mentioning regardless of your score.
Why the Score Matters Before Surgery
The STOP-Bang questionnaire is particularly important in surgical settings because undiagnosed sleep apnea creates real risks during and after anesthesia. People with OSA have narrower or more collapsible airways, which can complicate intubation and make sedation more dangerous. Anesthesia and pain medications further relax the muscles that keep the airway open, increasing the chance of breathing problems during recovery.
If you score 3 or higher before a planned surgery, your anesthesia team may take extra precautions: positioning you differently, choosing specific medications, or monitoring you more closely after the procedure. In some cases, a high score may lead to a sleep study and treatment with a breathing device before elective surgery proceeds.