Obstructive Sleep Apnea: The Screening Questions, What CPAP Actually Does and Why Driving Matters
Obstructive sleep apnea is a mechanical problem with a neurological consequence. The upper airway narrows or closes repeatedly during sleep, oxygen falls, and the brain rescues the situation with a brief arousal that restores breathing. Dozens or hundreds of times a night, and almost none of them remembered.
Which is why the usual way of finding out is not from the person affected. It is from a partner, or from blood pressure that will not come down, or from falling asleep at a desk at three in the afternoon having been in bed for eight hours.
📋 The eight questions: STOP-BANG
This is the screening questionnaire used in clinics and before surgery. It takes a minute and it is the most useful thing on this page. One point for each yes.
| Question | |
|---|---|
| S | Snoring loudly — louder than talking, or heard through a closed door |
| T | Tired, fatigued or sleepy during the day |
| O | Observed stopping breathing, choking or gasping during sleep |
| P | Pressure — being treated for high blood pressure |
| B | BMI over 35 |
| A | Age over 50 |
| N | Neck circumference over 43 cm in men, 41 cm in women — measured, not guessed |
| G | Gender male |
- 🟢 0 to 2 — low risk
- 🟡 3 to 4 — intermediate risk, worth testing
- 🔴 5 to 8 — high risk, test
Two or more yes answers among the first four, combined with male sex, a BMI over 35 or a large neck, also places someone in the higher-risk group regardless of the total. The questionnaire does not diagnose anything; it tells you whether a sleep study is worth asking for.
😴 And the sleepiness itself
The Epworth Sleepiness Scale asks how likely you are to doze in eight ordinary situations — reading, watching television, sitting as a passenger, lying down in the afternoon, sitting talking to someone, after lunch without alcohol, in a car stopped in traffic. Each scored 0 to 3, total out of 24. Above 10 is excessive daytime sleepiness; above 16 is severe. Worth scoring before treatment and again afterwards, because it measures what actually changed.
👩 Why it is missed in women. The textbook picture is a middle-aged man who snores. Women with obstructive sleep apnea more often present with insomnia, fatigue rather than sleepiness, morning headache, low mood and nonrestorative sleep, frequently with little or no reported snoring. The result is that they get treated for depression, anaemia or thyroid problems for years.
Risk also rises sharply after the menopause, narrowing a gap that is wide before it. New fatigue and broken sleep in that period deserve this on the list rather than being attributed to hormones alone.
📊 The test, and the number it produces
Diagnosis needs a sleep study. A home test is convenient and suitable when risk is high and there are no complicating conditions. A laboratory study records more — breathing, oxygen, heart rhythm, sleep stages, leg movements — and is used where the home test is inconclusive, where symptoms do not fit the result, or where heart or lung disease is present.
The headline figure is the apnea-hypopnea index, meaning breathing events per hour of sleep.
| AHI | Severity |
|---|---|
| 5 to 14 | Mild |
| 15 to 29 | Moderate |
| 30 or more | Severe |
The number alone does not decide treatment. How far the oxygen falls and for how long matters at least as much, and so do the symptoms and the cardiovascular picture: mild apnea with severe sleepiness and uncontrolled blood pressure is treated more urgently than moderate apnea in someone who feels well. Ask for the oxygen figures, not just the index.
❤️ What it does if left alone
The fatigue is what brings people in. The reasons to treat it go further.
| Consequence | Detail |
|---|---|
| Resistant high blood pressure | Obstructive sleep apnea is the commonest identifiable cause of blood pressure that will not come down on three drugs. Anyone in that situation should be screened for it before a fourth tablet is added |
| Atrial fibrillation | Strongly associated, and untreated apnea substantially raises the chance of the rhythm returning after ablation or cardioversion. Treating it improves those odds |
| Stroke and coronary disease | Risk rises with severity, through the repeated oxygen swings and blood pressure surges |
| Type 2 diabetes | Worsens insulin resistance independently of weight, and makes existing diabetes harder to control |
| Night-time urination | A direct and very common consequence, covered in our guide to waking at night to urinate |
| Accidents | At work and at the wheel. See the driving section below |
| Mood and concentration | Often diagnosed as depression or as attention problems first — the overlap with ADHD and daytime fatigue is a frequent source of confusion |
🛠️ CPAP, and why people abandon it
Positive airway pressure is the primary treatment and it works by splinting the airway open with a gentle stream of air. When used it reduces events to near zero, restores sleep structure and improves blood pressure, sleepiness and accident risk.
The difficulty is tolerance. A large share of people who stop did so for reasons that were fixable, and in the first fortnight. The fixes are mundane and they are the whole game.
- 😷 Mask fit and type. Nasal pillows, nasal mask or full face are different experiences, and so is a size up or down. A persistent leak at the eyes means the wrong mask, not the wrong patient
- 💧 Heated humidification for dry mouth, dry nose or nosebleeds
- 📈 Ramp, which starts the pressure low and builds it, so falling asleep does not feel like leaning out of a car window
- 👃 Treat the nose first. Chronic congestion, allergy or a deviated septum makes the whole thing intolerable. A nasal steroid spray, allergy treatment or an ENT opinion often converts a failure into a success
- 💬 Chin strap or a full face mask if the mouth falls open and the air escapes
- 📱 Read your own data. Modern machines report hours used, leak and residual events. Persistent sleepiness with a high leak figure is a mask problem; with a clean report it is something else
- ⏰ Give it a fortnight of every single night. Partial use produces partial benefit and the conclusion that it does not work
One technical point worth knowing: in a small number of people, central pauses appear after pressure therapy starts — treatment-emergent central sleep apnea. It often settles over weeks, and where it does not, the machine settings or the device type need changing. It is a known phenomenon rather than a sign that treatment failed.
🦷 When CPAP is not the answer
- 🦷 Mandibular advancement devices — a custom dental appliance that holds the lower jaw forward. Less effective than CPAP on the index but often better tolerated, which can make real-world results comparable. Suited to mild and moderate disease, and to people who travel constantly. Fitted by a dentist experienced in it, not a boil-and-bite device from the internet, which can move teeth and strain the jaw
- 🛌 Positional therapy where events are clearly worse lying on the back. Devices that discourage the supine position work for supine-predominant apnea and do nothing for the rest — the sleep study report says which group you are in
- ⚡ Hypoglossal nerve stimulation — an implanted device that activates the tongue muscles with each breath. For moderate to severe disease in people who genuinely cannot use CPAP, within specific criteria including weight and airway shape
- 🔪 Surgery — tonsillectomy where large tonsils are the obstruction, nasal surgery to enable CPAP rather than to cure apnea, soft palate surgery with mixed results, and maxillomandibular advancement, which is major surgery with high success in selected jaw anatomy
⚖️ Weight, with the actual numbers
Weight is the most modifiable factor and the advice usually arrives without any figure attached, which makes it easy to dismiss. The figure is worth having: around a 10 percent reduction in body weight is associated with roughly a quarter reduction in the apnea-hypopnea index, and larger losses can move someone a whole severity band or resolve mild disease.
There is a loop to break, which is why this is harder than it sounds and not a matter of discipline: untreated apnea fragments sleep, fragmented sleep worsens insulin resistance and increases appetite-driving hormones, and the resulting weight gain worsens the apnea. Treating the breathing usually has to happen alongside rather than after.
Worth knowing as of now: a GLP-1 based medicine, tirzepatide, has been approved specifically for moderate to severe obstructive sleep apnea in adults with obesity, on the strength of trials showing substantial reductions in the apnea index. It is a genuine addition to the options rather than a weight-loss drug being repurposed by marketing, and it is a conversation for a specialist.
🚫 What makes it worse, and one entry that matters more than the rest
⚠️ Sleeping tablets, sedatives and opioids worsen obstructive sleep apnea. They relax the airway muscles, blunt the arousal that ends each event, and deepen the oxygen falls. Benzodiazepines, the Z-drugs such as zolpidem and zopiclone, sedating antihistamines, muscle relaxants and opioid painkillers all do this to some degree.
This matters because the symptom people report is often poor sleep, and the response is often a sleeping tablet. Someone with untreated apnea who is given one is made measurably worse while feeling as though something is being done. If you snore, gasp at night or are sleepy by day, say so before accepting a sedative, and mention apnea specifically if it is already diagnosed.
- 🍷 Alcohol in the evening — relaxes the airway, suppresses the arousal response and deepens oxygen falls. A few hours clear of bedtime makes a measurable difference
- 🚭 Smoking, which inflames and swells the upper airway
- 🛏️ Sleeping on the back, in those for whom it is positional
- 👃 Untreated nasal obstruction, which both worsens apnea and wrecks CPAP tolerance
- ⏳ Too little time in bed. Using the machine faithfully for five hours a night produces five hours of treated sleep. Sleep opportunity is part of the treatment, not separate from it
🚗 Driving: the part with legal consequences
This is left out of most articles on the subject and it is the most consequential section here.
Untreated obstructive sleep apnea with daytime sleepiness increases the risk of a motor vehicle crash by a factor of roughly two to three. Effective treatment brings that risk back towards the general population level, and the improvement appears quickly once the machine is being used properly.
- 🛑 Do not drive while sleepy. Not with the window open, not with loud music, not with coffee and determination. The only reliable response is to stop, and a short nap in a safe place is the only thing that works
- ⚖️ There is usually a legal duty to declare it. In many countries a diagnosis of sleep apnea with excessive sleepiness must be reported to the driving licence authority, and failing to do so can invalidate insurance and carry a penalty. The rules are national, they change, and the licensing authority in your own country is the only reliable source — check it rather than assuming
- 🚛 Commercial and professional drivers face stricter requirements, often including documented treatment adherence from the machine data before returning to work. Vocational licences are commonly where this is detected first
- 📄 Treatment generally restores eligibility. Being diagnosed is not the thing that costs people their licence; being untreated and sleepy is
The same logic applies at work, around machinery, at height and on shift. Where irregular hours are the setting, our guide to shift work sleep disorder covers that overlap.
🏥 Before an operation, tell the anaesthetist
People with obstructive sleep apnea are at higher risk of breathing complications under general anaesthesia and sedation, because the drugs used do exactly what alcohol and sleeping tablets do, only more so, and the effect continues into the recovery period. This is precisely why STOP-BANG is used routinely in pre-operative clinics.
- 📣 Say that you have it, or that you snore and are sleepy if you have never been tested, at the pre-operative assessment and again on the day
- 💼 Take your own machine and mask into hospital and use them, including after the operation
- 💊 Flag opioid painkillers. Pain relief after surgery can be planned to use less of them where possible
- 🛏️ Expect closer monitoring afterwards, and ask for the head of the bed to be raised rather than lying flat
💊 Still sleepy with the airway treated
A minority of people remain significantly sleepy despite good therapy. Before that is accepted as residual, five things get checked, because four of them are commoner than the fifth.
- ⏱️ Actual usage — hours per night from the device, not impression
- 💨 Leak and residual events on the same report
- 🛏️ Sleep opportunity — enough hours in bed to be rested
- 💊 Other causes — sedating medication, depression, an underactive thyroid, iron deficiency, restless legs, or another sleep disorder such as narcolepsy. The wider differential is in our guide to persistent tiredness
- 🏃 Lifestyle — alcohol, caffeine timing, shift patterns
Where the airway is genuinely treated, usage is good and nothing else explains it, a wakefulness-promoting medicine is a licensed option. Waklert (Armodafinil) is approved as an adjunct to improve wakefulness in adults with excessive sleepiness associated with obstructive sleep apnea.
- 🔹 150 mg or 250 mg once daily in the morning for obstructive sleep apnea
- ⚡ It treats the sleepiness, not the apnea. The airway is still closing and the oxygen is still falling; the drug removes the warning signal. It is an addition to primary therapy and never a replacement for it, which is the single most important sentence about this drug
- 📉 Related comparisons are in our guide to armodafinil versus modafinil, and the range is in the anti-narcoleptic category
⚠️ What has to be known before taking it.
Rash. Rare but serious skin and multi-organ hypersensitivity reactions have occurred, including severe blistering rashes. Any rash in the early weeks means stopping and seeking assessment the same day, not waiting to see.
Contraception. It induces liver enzymes and reduces the effectiveness of hormonal contraception — the pill, patch, ring and implant — during treatment and for about a month after stopping. An additional or alternative method is needed. This is routinely not mentioned and it has obvious consequences.
Mind and heart. Anxiety, agitation, insomnia and, uncommonly, more serious psychiatric reactions. Blood pressure and heart rate can rise, and it is avoided after a recent heart attack or with unstable angina.
Other. It is a controlled substance in many countries, interacts with several medicines including ciclosporin, and should not be taken late in the day because it will prevent sleep.
📞 When to seek help
- A STOP-BANG score of 3 or more, or an Epworth score above 10 — ask for a sleep study
- Witnessed pauses in breathing, choking or gasping — test regardless of the score
- Falling asleep while driving, or near-misses — stop driving and get assessed urgently
- Blood pressure not controlled on three medicines — screen for apnea before adding a fourth
- Atrial fibrillation, particularly before or after ablation or cardioversion
- Fatigue, insomnia and morning headache in a woman, especially around or after the menopause — raise apnea specifically
- Being offered a sleeping tablet or sedative while snoring or sleepy — mention apnea first
- Any operation planned — tell the anaesthetist and take the machine in
- Abandoning CPAP — go back and get the mask, humidity, pressure and nose sorted rather than giving up on the treatment
- Still sleepy with good usage and a clean device report — time to look at the other causes
- Any rash in the first weeks of armodafinil — stop and seek assessment the same day
❓ Frequently asked questions
How do I know if I might have sleep apnea?
Score yourself on STOP-BANG: loud snoring, daytime tiredness, observed breathing pauses, treated high blood pressure, BMI over 35, age over 50, neck over 43 cm in men or 41 in women, and male sex. Three or more yes answers is worth testing.
What does my AHI number mean?
Breathing events per hour of sleep: 5 to 14 is mild, 15 to 29 moderate, 30 or more severe. The number alone does not decide treatment — how far oxygen falls, the symptoms and the cardiovascular picture matter as much, so ask for the oxygen figures too.
Can you have sleep apnea without snoring?
Yes, and this is why it is under-diagnosed in women, who more often present with insomnia, fatigue, morning headache and low mood rather than snoring. Risk also rises sharply after the menopause.
Can I take sleeping tablets if I have sleep apnea?
They make it worse. Benzodiazepines, Z-drugs, sedating antihistamines and opioids relax the airway, blunt the arousal that ends each event and deepen the oxygen falls. Mention apnea, or snoring and sleepiness, before accepting a sedative.
How much weight loss makes a difference?
Around a 10 percent reduction in body weight is associated with roughly a quarter reduction in the apnea-hypopnea index, and larger losses can move a whole severity band. A GLP-1 based medicine is now also approved specifically for moderate to severe apnea with obesity.
I cannot tolerate CPAP. What now?
Most intolerance is fixable: mask type and size, heated humidification, a ramp setting, and treating nasal congestion, which is the commonest hidden reason. If it genuinely cannot be used, a custom mandibular advancement device, positional therapy, nerve stimulation or surgery are the alternatives.
Do I have to tell the licensing authority about sleep apnea?
In many countries a diagnosis with excessive sleepiness must be declared, and failing to do so can invalidate insurance. Rules are national and change, so check your own licensing authority. Treatment generally restores eligibility — being untreated and sleepy is what costs licences.
Why does my blood pressure stay high despite medication?
Obstructive sleep apnea is the commonest identifiable cause of blood pressure that will not come down on three drugs. Screening for it before adding a fourth tablet is worth asking about directly.
I am on CPAP and still exhausted. Why?
Check usage hours, leak and residual events on the device report, then sleep opportunity, then other causes — sedating medicines, depression, thyroid problems, iron deficiency, restless legs or another sleep disorder. Genuine residual sleepiness is the last conclusion, not the first.
Can armodafinil replace CPAP?
No, and this is the most important point about it. It improves wakefulness while the airway continues to close and the oxygen continues to fall, so it removes the warning signal rather than the problem. It is only an addition to primary therapy.
📑 Sources and editorial
- American Academy of Sleep Medicine guidance on the diagnostic testing and management of obstructive sleep apnea in adults, including home versus laboratory testing
- Validation studies of the STOP-BANG questionnaire and of the Epworth Sleepiness Scale, including their use in pre-operative screening
- Scoring definitions for the apnea-hypopnea index and oxygen desaturation measures
- Guidance on resistant hypertension identifying obstructive sleep apnea as the commonest identifiable secondary cause, and studies of apnea and atrial fibrillation recurrence after ablation
- Cohort studies of weight change and apnea-hypopnea index, and the randomised trial programme supporting tirzepatide in moderate to severe obstructive sleep apnea with obesity
- Reviews of sedative-hypnotic, benzodiazepine and opioid effects on upper airway collapsibility and arousal threshold
- Meta-analyses of motor vehicle crash risk in untreated obstructive sleep apnea and of risk reduction with positive airway pressure therapy
- Society guidance on perioperative management of patients with known or suspected obstructive sleep apnea
- Evidence on mandibular advancement devices, positional therapy, hypoglossal nerve stimulation and upper airway surgery, and on treatment-emergent central sleep apnea
- Prescribing information for armodafinil, including dosing in obstructive sleep apnea, serious dermatological and hypersensitivity reactions, psychiatric and cardiovascular precautions, and the interaction with hormonal contraception
- Reviews of sex differences in the presentation and diagnosis of obstructive sleep apnea, including after the menopause
- Related reading: narcolepsy, persistent tiredness, shift work sleep disorder, armodafinil versus modafinil
- Related products: Waklert (Armodafinil), anti-narcoleptic category
- RXshop Editorial Team — reviewed by James Carter, MD — Neurologist & Sleep Medicine Specialist
Medical Disclaimer: The information in this article is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek guidance from a qualified healthcare provider with any questions you may have regarding a medical condition, and before starting, stopping or changing any medication.