Central vs Obstructive Sleep Apnoea: What Is the Difference?

Quick answer: Both central and obstructive sleep apnoea involve breathing repeatedly stopping during sleep, but the machinery failing is different. In obstructive sleep apnoea, your body keeps trying to breathe while the airway physically collapses. In central sleep apnoea, the airway may be wide open while the brain briefly stops sending the signals that drive breathing. The difference matters, because treatments that work for one can be unhelpful for the other.

The mechanics: airway collapse versus brain signalling

Think of breathing during sleep as two jobs happening at once. One is mechanical: muscles in the throat hold a passageway open while the diaphragm pumps air through it. The other is control: a region of the brainstem reads carbon dioxide levels and adjusts the effort of breathing second by second.

In obstructive sleep apnoea (OSA), the control centre keeps firing normally, the chest and diaphragm keep heaving, but the throat has collapsed and no air moves. The blockage is physical: relaxed tissue, tongue position, tonsils or weight around the neck. Snoring, gasps and snorts are the sound of air forcing its way through a narrowed or reopened airway.

In central sleep apnoea (CSA), the mechanics are fine and the airway is open, but the control centre pauses. The brain simply issues no command to breathe for a stretch of seconds, so the diaphragm goes quiet. Because there is no effort against a blocked airway, CSA often produces little snoring, and the pauses look like calm silence on a recording. Bed partners may instead notice restless or jet-like breathing patterns at night.

What causes each condition

OSA is the far more common of the two in Australia. Its drivers are largely anatomical and lifestyle-related: excess weight around the neck, a naturally narrow throat or jaw, enlarged tonsils, nasal obstruction, alcohol, ageing muscle tone and back sleeping. Men are affected more than women, with risk rising around mid-life and again after menopause.

CSA is less common and usually points to something affecting the brain or the heart:

• Heart failure, the best-established association, often producing a distinctive pattern known as Cheyne-Stokes breathing: cycles in which breathing builds to a peak, then fades to a pause, then builds again.
• Stroke or other neurological conditions that disturb the brainstem circuits governing breathing.
• Opioid medications, which dampen the brain's response to carbon dioxide and can slow or pause breathing during sleep.
• High altitude, where thin air can destabilise the breathing control system, typically resolving on return to lower ground.
• Certain other medications and conditions, sometimes including stimulants or kidney disease, and some cases have no clear cause.

Some people have both patterns on a single night, with central events appearing once an airway problem has been treated. That is why interpretation belongs with a physician rather than with the raw report alone.

How the symptoms compare

There is overlap: both conditions cause unrefreshing sleep, daytime fatigue, morning headaches and night-time awakenings. But the texture differs.

OSA tends to come with heavy snoring, witnessed pauses, gasping and choking, dry mouth, night-time toilet trips and loud nights that bother a partner. CSA may be quieter on the surface: less snoring, but difficulty staying asleep, unexplained awakenings with a racing heart, and daytime tiredness that has no obvious explanation, especially in someone who has heart failure or has had a stroke. Fatigue and cognitive fog occur in both.

One practical implication: if you snore loudly, OSA is the likely suspect. If your breathing is "too quiet" and your nights feel unsettled, CSA is worth the physician's attention, particularly if you have heart disease or take opioid medication.

Why diagnosis needs the right study

Distinguishing the two is exactly what a well-designed sleep study is for. The recording has to measure not just airflow and oxygen, but the actual effort of breathing: chest and abdominal movement, or airflow patterns that reveal whether the body is trying to breathe during each pause.

A laboratory study, attended by staff overnight, measures this comprehensively, along with brain waves, heart rhythm and leg movements. Modern home sleep tests are designed to distinguish obstructive from central events as long as they record airflow and effort properly, and are well suited to straightforward cases. Our sleep study near me guide compares home and clinic testing, and finding a properly equipped service through our sleep clinic near me directory means the recording will capture the details a physician needs. Whatever the format, the final read belongs to a sleep doctor, because the pattern on the page has to be matched against your heart history, medications and altitude exposure.

Treatment differences

Because the mechanisms differ, so do the treatments, and one machine setting does not suit both.

For OSA, the standard first-line treatment is CPAP: a small pump holding the airway open with gentle air pressure through a mask overnight. Losing weight, side sleeping, reducing alcohol and managing nasal congestion all support CPAP or occasionally replace it in milder cases. Oral devices repositioning the jaw are another option some people use.

For CSA, plain CPAP is often not enough, and sometimes not appropriate at all. The airway is already open; what is missing is the drive to breathe. Specialist options include bilevel devices that deliver a small assisted breath when the machine detects none happening, and adaptive servo-ventilation, often shortened to ASV, which continuously learns your breathing pattern minute by minute and nudges it back toward normal. A key caution: ASV is not suitable for everyone, and in people with weak hearts of a particular type it has been shown to be unhelpful, which is precisely why heart function is assessed before such a device is prescribed. Treating the underlying driver, such as heart failure, or adjusting opioid medication with the prescribing doctor, often does more for central apnoea than any change of device.

Frequently Asked Questions

Which is worse, central or obstructive sleep apnoea?

Neither label automatically means worse; severity is judged by event frequency, oxygen dips and symptoms, not by type. Untreated OSA is more common and its long-term effects on blood pressure and heart health are well described. Untreated CSA often signals an underlying heart or neurological problem that itself needs attention. Either diagnosis deserves prompt, structured follow-up with a sleep physician and your GP.

Can obstructive sleep apnoea turn into central sleep apnoea?

They often coexist. Until OSA is treated, central events can be hidden behind the obstruction and only appear on a follow-up study once the airway opens. Some people then need a different device mode or medication review. This is a recognised part of managing apnoea rather than a treatment failure, and it is an essential reason specialists like to review the actual recording rather than relying on a summary number.

Is Cheyne-Stokes breathing the same as central sleep apnoea?

Not identical, but closely related. Cheyne-Stokes breathing describes a waxing and waning cycle of airflow, where breaths grow deeper, then shallower, then pause, then build again. It is most often seen in heart failure and frequently accompanies central sleep apnoea on overnight recordings. Seeing that pattern in a study prompts the physician to look closely at heart function alongside the apnoea itself.

Can central sleep apnoea be cured?

Sometimes, when a fixable cause is addressed, such as an opioid medication that can be adjusted or high altitude that resolves on return. In heart failure, treatments aimed at the heart often reduce central events significantly. Many cases settle into long-term management with the right device mode rather than a one-off cure. Outcomes vary, so the plan should come from a sleep physician working with your GP.