A STOP-BANG score is a number from 0 to 8 that estimates your risk of having obstructive sleep apnea (OSA). Each point comes from a yes/no answer to one of eight questions about your symptoms, body measurements, and demographics. A score of 3 or higher flags you as high risk, while a score below 3 puts you in the low-risk category. It’s one of the most widely used screening tools for sleep apnea because it takes about two minutes to complete and doesn’t require any special equipment.
What Each Letter Stands For
The name “STOP-BANG” is an acronym. The first four letters cover symptoms and health history:
- S (Snoring): Do you snore loudly enough to be heard through closed doors, or does your bed partner nudge you for snoring at night?
- T (Tired): Do you often feel tired, fatigued, or sleepy during the daytime, such as falling asleep while driving or during conversation?
- O (Observed): Has anyone seen you stop breathing, choke, or gasp during sleep?
- P (Pressure): Do you have high blood pressure, or are you being treated for it?
The second four letters cover physical and demographic factors:
- B (BMI): Is your body mass index greater than 35?
- A (Age): Are you older than 50?
- N (Neck circumference): Is your neck circumference 16 inches (40 cm) or larger, measured around the Adam’s apple?
- G (Gender): Are you male?
You score one point for every “yes.” The total gives your risk level.
How the Score Translates to Risk
A score below 3 means low risk of obstructive sleep apnea. A score of 3 or 4 and above means high risk. There’s no formal “moderate” category in most versions of the tool, though some clinicians treat a score of 3 as intermediate and reserve “high risk” for 5 and above.
The questionnaire is deliberately designed to cast a wide net. For moderate-to-severe sleep apnea, it catches roughly 91% of people who actually have the condition. That sensitivity comes at the cost of specificity: only about 23% of people who score below the threshold are truly free of moderate-to-severe OSA. In practical terms, this means a high score is a strong signal that something is going on, but a low score doesn’t completely rule it out. When the cutoff of 3 is used, the tool is 93% sensitive for moderate OSA and 100% sensitive for severe OSA.
What Happens After a High Score
A high STOP-BANG score is a screening result, not a diagnosis. If you score 3 or higher, the typical next step is a sleep study called polysomnography. This can be done in a sleep lab overnight, or increasingly, at home with a portable device. A home study uses sensors that track your breathing effort, blood oxygen levels, body position, and brain activity while you sleep in your own bed. A trained technician sets up the device beforehand, and the recording runs unattended through the night.
The sleep study measures how many times per hour your breathing partially or fully stops. That number, called the apnea-hypopnea index, is what confirms or rules out a sleep apnea diagnosis and determines its severity.
STOP-BANG vs. the Epworth Sleepiness Scale
Another common screening tool you might encounter is the Epworth Sleepiness Scale (ESS), which asks you to rate how likely you are to doze off in eight everyday situations, like sitting and reading or watching TV. The maximum score is 24, and a score of 10 or higher suggests excessive daytime sleepiness.
The key difference is what each tool measures. The Epworth scale is entirely subjective: it relies on your own perception of how sleepy you feel. The STOP-BANG questionnaire leans more heavily on objective factors like neck size, BMI, and blood pressure. Head-to-head comparisons consistently show that STOP-BANG is better at catching OSA across all severity levels, with higher predictive accuracy overall. The Epworth scale, on the other hand, tends to be better at ruling people out (higher specificity).
Some clinicians use both tools together. Combining STOP-BANG with the Epworth scale boosts specificity significantly, from around 35-47% up to 59-67%, depending on OSA severity. This pairing reduces the number of people flagged unnecessarily while still catching most true cases.
Limitations Worth Knowing
The STOP-BANG questionnaire was originally developed for pre-surgical screening, and it works best in populations where sleep apnea is relatively common, like people with cardiovascular risk factors or those preparing for surgery. In younger, leaner populations, the tool’s high false-positive rate can send a lot of healthy people toward unnecessary testing.
The gender question also means that women start with one fewer potential point. Since women develop sleep apnea at lower rates but are also more likely to be underdiagnosed, some clinicians adjust their interpretation accordingly. A woman scoring 3 may warrant the same attention as a man scoring 4 or 5.
The questionnaire also can’t distinguish between obstructive sleep apnea and central sleep apnea, which has a different mechanism. It’s a first-pass filter, not a replacement for a proper sleep evaluation.