Sleep, Sleep Apnea, and Obesity

The combination that matters is unrefreshing sleep plus a risk factor. You were in bed long enough, and you still wake up tired.

Resist the assumption that snoring is the entry ticket. It's the symptom everyone knows, and it's the least reliable one. Significant apnea occurs without much snoring, and loud snoring occurs without apnea. If you're waiting to snore before you get evaluated, you may wait a long time.

Things worth writing down before your appointment: whether anyone has seen you stop breathing or gasp, morning headaches, waking to urinate more than once, dry mouth, drowsiness while driving, blood pressure that needs more than one medication, or atrial fibrillation.

If you sleep alone, a phone app that records sound overnight is imperfect but genuinely useful. Many diagnoses start with someone playing a recording for their doctor.

STOP-BANG is the screening tool most clinicians use. Eight yes/no questions, one point each. It's designed to be very good at not missing people, which means a high score is a reason to test, not a diagnosis.

S · Snoring loudly?
T · Tired, fatigued, or sleepy during the day?
O · Observed to stop breathing, choke, or gasp in your sleep?
P · Pressure: do you have, or are you treated for, high blood pressure?
B · BMI over 35?
A · Age over 50?
N · Neck circumference 16 inches or more (women) / 17 inches or more (men)?
G · Gender: male?

0–2 is low risk. 3–4 is intermediate, worth discussing. 5–8 is high risk, and higher scores predict more severe disease. One caveat: two or more “yes” answers on the STOP half, combined with male sex, a BMI over 35, or a large neck, also indicates high risk even if your total is 3 or 4.

Other tools your clinician may use instead include the Berlin Questionnaire, the Epworth Sleepiness Scale, and NoSAS. All of them are quick to complete and none of them are diagnostic on their own. They tell you whether to test, not whether you have it.

Worth knowing: STOP-BANG is not only a screener. It is the instrument the 2025 ICHOM international standard selected for tracking sleep quality as an outcome in adult obesity care, at baseline and every six months. The same eight questions that tell you whether to get tested also tell your care team whether treatment is working.

Bring the score to your appointment. It moves the conversation from “I think I sleep badly” to a number your clinician already knows how to act on.

A sentence that works: “I'm tired all day, it doesn't improve with more sleep, and my STOP-BANG score is five. I'd like to be evaluated for sleep apnea.”

Your primary care clinician can often order testing directly. You don't always need a sleep specialist first. Primary care is where most of these diagnoses should be starting, and the main reason they aren't is that the conversation never happens.

If you're told to just lose weight and come back, it's reasonable to ask to be tested in the meantime. The two aren't alternatives, and as the treatment walkthrough explains, they now work best together.

Reasons your clinician may route you to a sleep physician instead: significant heart or lung disease, suspected narcolepsy or another sleep disorder, neuromuscular conditions, or a home test that came back negative while symptoms continue.

Home sleep apnea test. A small kit you take home, typically a finger sensor, a nasal cannula, and a chest belt, worn in your own bed. Convenient, much less expensive, and appropriate for most uncomplicated adults with a high likelihood of moderate-to-severe OSA. It is indicated for diagnosing OSA specifically, not other sleep disorders.

In-lab polysomnography. The standard diagnostic test, done overnight at a sleep center with fuller monitoring including brain waves and leg movements. It can diagnose the full range of sleep disorders. The trade-offs are cost, travel, and sleeping somewhere unfamiliar.

One important caveat: a home test can underestimate severity, because it measures recording time rather than actual sleep time. It can't tell how much of the night you were awake, which raises the risk of a false negative. A negative home test in someone with convincing symptoms should be followed up, not filed away.

Two definitions first, because they're what the machine is counting. An apnea is a drop in airflow of at least 90% lasting 10 seconds or more. A hypopnea is a partial closure, at least a 30% drop for at least 10 seconds, accompanied by an oxygen dip or an arousal.

The headline number is the AHI, or apnea-hypopnea index, the average number of those events per hour.

Under 5 · normal.
5 to under 15 · mild.
15 to under 30 · moderate.
30 or more · severe.

Also look at the oxygen saturation nadir (how low your oxygen dropped) and the oxygen desaturation index. Two people can share an AHI and have very different degrees of oxygen strain overnight.

Ask for a copy of the report. If you later change treatment or lose a substantial amount of weight, the original numbers are what any repeat study gets compared against.

A diagnosis is the start of a conversation, not the end of one. Treatment choice depends on severity, on your anatomy, on whether you have cardiovascular disease, and substantially on what you will actually use every night.

The most effective treatment in the world does nothing sitting in a closet. Say out loud what you think you can tolerate. That is clinical information, not a confession.

If your weight is part of the picture, treating both sides at once is now a well-supported strategy rather than a sequence. The second walkthrough covers the options.

And if you do start treatment: don't stop it on your own if you lose weight and feel better. That's a great problem to have, and it's a reason to repeat the sleep study, not a reason to quietly retire the machine.