Snoring and unrefreshing sleep: sleeping long enough does not mean sleeping well enough
Division of Pulmonary Medicine, Taipei Veterans General Hospital Hsinchu Branch · Symptom triage
Related pagesFind your symptomThe complete guide to OSAInterpreting a sleep report （中文）
Three sentences first
- Loud snoring does not mean severe disease. What really counts is “whether anyone has witnessed you stop breathing” and “whether you are sleepy during the day”.
- Sleep apnoea is linked to hypertension, arrhythmia, stroke and poor blood sugar control — and it can be treated.
- Thin people get it too. The craniofacial structure of people of Asian descent means it can appear at a lower body weight, so “I am not overweight” cannot be used as a reason to rule it out.
🚩 With any of these, do not put it off any longer
- Nodding off while driving a car or riding a motorcycle, or nearly having an accident through losing concentration.
- A member of your family has witnessed you stop breathing in your sleep, perhaps frightening them enough to shake you awake.
- Waking in the night fighting for breath or choking, or waking with a feeling of suffocation.
- A headache and a dry mouth on waking, almost every day.
- Blood pressure that stays out of control however many drugs are added (resistant hypertension).
- Atrial fibrillation, heart failure or a previous stroke, together with snoring.
- Daytime sleepiness in high-risk work such as driving, working at height or operating machinery.
The first of these above all. The accident risk of driving while sleepy is comparable to that of drink-driving — until this has been settled, avoid driving when tired and avoid long journeys, and have someone else drive if need be.
Why does the breathing stop?
Once you are asleep, the muscle tone around the upper airway falls. If the airway is already on the narrow side (a receding lower jaw, an enlarged tongue base, large tonsils, fat deposition), the negative pressure generated as you breathe in can suck the airway shut — and that is obstructive sleep apnoea.
The airway collapses → the blood oxygen falls → the brain is forced to wake briefly to open the airway → you fall asleep again → it collapses again. This cycle may happen dozens or even hundreds of times in a night, and you remember none of it. The result: eight hours in bed, but not one spell of proper deep sleep, and a whole night of repeated oxygen dips.
These two things cause everything that follows
- Intermittent hypoxia: the repeated fall and recovery of oxygen causes oxidative stress and damage to the lining of the blood vessels, and is associated with a rise in the risk of hypertension, coronary heart disease and stroke.
- Fragmented sleep: the sympathetic nervous system is activated all night, leading to daytime sleepiness, poorer attention and memory, unstable mood, and worse regulation of blood sugar and blood pressure.
What else might snoring be?
Obstructive sleep apnoea (OSA)
Strong evidenceThe one that has to be settled first. Snoring + witnessed pauses in breathing + daytime sleepiness is the classic combination of three.
Clues: a thick neck, a high BMI, a receding lower jaw, high blood pressure, being male or a post-menopausal woman, increasing age. But thin people can have it just the same.
Simple snoring (primary snoring)
Strong evidenceNoise only, with no fall in blood oxygen and no interruption of sleep. The effect on health is limited; the person most troubled by it is whoever shares the bed.
Clues: no daytime sleepiness, no witnessed pauses in breathing, normal blood pressure. But only a sleep study can tell it apart from OSA — it cannot be judged by how it feels.
Snoring caused by a blocked nose
ModerateNasal allergy, a deviated septum or nasal polyps raise the resistance of the nose, you are forced to breathe through your mouth, and the snoring gets worse.
Clues: a long-standing blocked nose, mouth breathing, a dry mouth in the morning. Treating the blocked nose can improve the snoring and make CPAP more comfortable to use, but treating the nose alone usually cannot cure OSA.
Not enough sleep, or problems with sleep habits
Strong evidenceThe commonest and most often overlooked reason for “never feeling rested” is simply not sleeping enough, or an irregular routine, screens before bed, or shift work.
Clues: less than six hours’ sleep on weekdays, a lot of catching up at weekends, no snoring, no witnessed pauses in breathing.
Other causes of daytime sleepiness
ModerateAnaemia, an underactive thyroid, depression, drug side effects (sedatives, antihistamines, some blood pressure medicines) and restless legs syndrome all leave people feeling poor during the day.
Clues: severe sleepiness without snoring; or sleepiness that still does not improve after OSA has been treated. Blood tests and a full review of your medicines help a great deal.
Central sleep apnoea
ModerateNot a collapsing airway, but the brain briefly forgetting to give the instruction to breathe. Common in heart failure, after a stroke, and in people taking opioid painkillers.
Clues: no effortful movement of the chest and abdomen during the pause, a history of heart failure or stroke. A full sleep study is needed to tell it apart from the obstructive form, and the treatment is different too.
Which tests are usually done?
It answers: how many times did the breathing stop in a night? How far did the oxygen fall? Is it obstructive or central? This is the gold standard for diagnosis.
An overnight stay in a sleep centre, with a full recording of brain waves, eye movements, muscle activity, airflow, chest and abdominal movement, blood oxygen and the ECG. It is the one that has to be done where there are complex coexisting illnesses or a suspicion of the central form.
It answers: is there moderate to severe obstructive sleep apnoea?
A simpler device worn at home, in your own bed. It suits people who are at moderate to high risk and have no serious heart or lung disease. Convenient, with a short wait, but if the result is negative and the symptoms are clear, a PSG is still needed to settle it.
They answer: how high is the risk? Is a test worth arranging? These are screening tools and cannot be used to make a diagnosis.
The self-assessment tool above is built on these two.
It answers: at which level is the obstruction? The nose, the tonsils, the tongue base, the soft palate. Assessed by endoscopy in the ENT department, and particularly important for anyone considering surgery or a dental device.
It answers: might the sleepiness have another cause? Anaemia and an underactive thyroid are common coexisting factors and easy to treat.
The treatment options
| Approach | Who it suits | Evidence |
|---|---|---|
| Continuous positive airway pressure (CPAP) | First-line for moderate to severe OSA. Airflow holds the airway open | Strong evidence |
| Weight loss | Anyone overweight. Losing weight clearly reduces the severity, and in some people the condition resolves | Strong evidence |
| Training to sleep on your side | People of the “position-dependent” type, who are clearly worse lying on their back | Moderate |
| A mandibular advancement device | Mild to moderate disease, or people who cannot tolerate CPAP. Made by a dentist | Moderate |
| Surgery | People with a clear anatomical obstruction (enlarged tonsils, a deviated septum) | Moderate |
| Avoiding alcohol and sedatives before bed | Everyone. Both lower the muscle tone of the upper airway and make the obstruction worse | Strong evidence |
One thing to be honest about, on CPAP and cardiovascular risk
CPAP is clearly proven to improve snoring, daytime sleepiness, blood pressure and quality of life. But on the question of whether it can reduce cardiovascular events in people who already have cardiovascular disease, the result of the large randomised trial SAVE was neutral (it did not reach statistical significance), which is generally thought to be related to the low number of hours a night the device was used in the trial.
So the reasonable position is this: the core value of CPAP lies in improving symptoms, quality of life and blood pressure; whether to use it as a means of managing cardiovascular risk should be discussed individually with your doctor. How we label evidence →
Common questions
I snore very loudly. Does that mean it is more severe?
Not necessarily. The volume of snoring depends on how the airway vibrates, and bears no direct relation to the severity of the obstruction. Some of the most severely affected people are quiet, because the airway collapses completely — and then there is one sudden loud noise as breathing resumes. What really has predictive value is “whether anyone has witnessed you stop breathing”, “whether you are sleepy during the day” and “whether you have high blood pressure” — which is exactly what the self-assessment tool above asks about.
I am very thin, so I probably do not have it, do I?
You can. Weight is an important risk factor but not the only one. A receding lower jaw, a small chin, an enlarged tongue base or tonsils, and a deviated nasal septum all leave the airway naturally narrow, and the craniofacial structure of Asian populations means the condition can appear at a comparatively low BMI. Age itself also lowers the muscle tone of the upper airway. If you are thin but have clear symptoms, you should be investigated all the more, because the cause is often structural and the management is different.
Do I have to spend the night in hospital?
Not necessarily. Home sleep apnoea testing lets you sleep in your own bed, and for people at moderate to high risk with no serious heart or lung disease it is a reasonable choice, usually with a shorter wait as well. But if you have heart failure, have had a stroke, take opioid painkillers, or the central form is suspected, you need a full PSG in a sleep centre. Which one suits you is for a doctor to judge from your symptoms and your other conditions.
Can people actually keep CPAP on? Does it become a dependence?
CPAP does not cause dependence — it is not a drug, and when you stop using it your breathing returns to how it was before; it does not get worse. Problems with getting used to it genuinely do exist, commonly a leaking mask, a dry mouth and the feeling of the pressure. Most of these can be solved by changing the style of mask, adding heated humidification and adjusting the pressure mode; the key is to come back in the first fortnight for adjustment rather than giving up. The evidence shows that the more hours it is used, the clearer the improvement in symptoms.
Will my blood pressure improve after treatment?
It may, but by how much varies from person to person. In people with resistant hypertension together with OSA, the improvement in blood pressure with CPAP is usually clearest. CPAP is not a substitute for blood pressure medicines, though — it should be seen as one part of “making blood pressure easier to control”, not as an alternative. After starting treatment, keep measuring your blood pressure and discuss adjusting your medicines with your doctor.
What to do next
If the self-assessment above shows moderate risk or more, the next step is to arrange a sleep study. When you come to clinic, bring what your family have witnessed (pauses in breathing, waking fighting for breath) with you — that is the key information you cannot provide yourself.
References
- Kapur VK, Auckley DH, Chowdhuri S, et al. Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2017;13(3):479-504.
- Patil SP, Ayappa IA, Caples SM, et al. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2019;15(2):335-343.
- Chung F, Yegneswaran B, Liao P, et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea. Anesthesiology. 2008;108(5):812-821.
- Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991;14(6):540-545.
References follow the ICMJE (Vancouver) style. Guidelines and official documents are given with their version or year of publication; legislation and National Health Insurance (NHI) rules are given with the responsible authority and the version date. Last checked: 8 October 2026.
This content is health information. It is for reference only and cannot replace a professional medical diagnosis. The self-assessment on this page is based on STOP-BANG and the Epworth sleepiness scale and is a screening tool; it cannot be used to diagnose sleep apnoea, which requires a sleep study to confirm. All of the working is done on your own device, and your answers are not uploaded and are not stored. This site records only anonymous usage statistics (for example, how many people read this page to the end, how many complete a self-assessment, and which band the result falls into). It does not include what you answered, and it sets no cookies. See the privacy notice for details.
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