Central Sleep Apnea vs Obstructive Sleep Apnea: Key Differences, Causes, and Treatment

Short answer: Obstructive sleep apnea (OSA) happens when the muscles in your throat relax and physically block your airway during sleep. Central sleep apnea (CSA) happens when your brain temporarily stops sending the signal to breathe at all, even though your airway stays open. OSA is far more common, usually causes loud snoring, and is typically treated with CPAP. CSA is less common, often occurs without snoring, and may require a different type of therapy called adaptive servo-ventilation (ASV) or bilevel support.

Sleep apnea affects an estimated 30 million adults in the United States, and most go undiagnosed. While both obstructive sleep apnea and central sleep apnea cause repeated pauses in breathing during sleep, the underlying cause — and the right treatment — are very different. Getting this distinction right matters, because the wrong device can leave a CSA patient untreated and worsen outcomes for someone with heart failure.

As a licensed Registered Respiratory Therapist (RRT), I've worked with patients on both sides of this diagnosis. Here's a clear, clinical breakdown of what separates OSA from CSA, how each is diagnosed, and what treatment actually looks like for each.

What Is Obstructive Sleep Apnea (OSA)?

Obstructive sleep apnea is the most common form of sleep apnea, and it's a mechanical problem. During sleep, the muscles at the back of your throat relax. In people with OSA, these tissues relax enough to partially or fully collapse onto the airway, blocking airflow even though your brain is still trying to breathe.

Each blockage is called an apnea (complete pause) or hypopnea (partial reduction in airflow). Your brain senses the drop in oxygen and briefly wakes you — often without you remembering it — so your airway muscles tighten back up and breathing resumes, frequently with a gasp or loud snore.

Common Symptoms of OSA

• Loud, chronic snoring — often the first sign a partner notices
• Waking up gasping or choking
• Excessive daytime sleepiness, even after a full night in bed
• Morning headaches
• Irritability, mood changes, or depression
• Difficulty concentrating or memory problems

Risk Factors for OSA

• Excess body weight, particularly around the neck
• Older age
• Family history of sleep apnea
• Naturally narrow airway, large tonsils, or a recessed jaw
• Smoking and alcohol use, especially close to bedtime
• Male sex (though OSA is significantly underdiagnosed in women)

Left untreated, OSA raises the long-term risk of high blood pressure, type 2 diabetes, heart disease, and cognitive decline affecting memory and focus.

What Is Central Sleep Apnea (CSA)?

Central sleep apnea is a neurological problem, not a mechanical one. Your airway stays open, but your brainstem temporarily stops sending the signal to your breathing muscles. Breathing usually restarts on its own once carbon dioxide builds up enough to trigger the next breath.

CSA is far less common than OSA and is strongly linked to underlying medical conditions — particularly heart failure, stroke, and certain neurological disorders. Several recognized patterns of CSA exist:

• Cheyne-Stokes breathing — a cyclical pattern of breathing that gradually speeds up, slows down, and pauses, commonly seen in heart failure patients
• Drug-induced central apnea — associated with opioid medications
• High-altitude periodic breathing — triggered by low oxygen at elevation
• Idiopathic CSA — no identifiable cause found

Common Symptoms of CSA

• Abrupt awakenings with shortness of breath
• Insomnia or difficulty staying asleep
• Excessive daytime sleepiness
• Morning headaches
• Difficulty concentrating, irritability

Notably, CSA usually does not cause loud snoring — this is one of the more reliable clues separating it from OSA, though it isn't a substitute for a sleep study.

Risk Factors for CSA

• Heart failure with reduced ejection fraction
• Stroke or other neurological conditions
• Opioid medication use
• Older age
• Male sex
• Recent travel to or residence at high altitude

Complex Sleep Apnea: When Both Overlap

Some patients have features of both conditions — a mechanical airway blockage alongside a breathing-signal problem. This is called complex sleep apnea or treatment-emergent central sleep apnea, and it sometimes only becomes apparent after starting CPAP therapy for OSA. If central apneas appear or worsen on standard CPAP, your sleep physician may recommend a different therapy mode such as bilevel (BiPAP) support or ASV.

OSA vs CSA: Side-by-Side Comparison

How Sleep Apnea Is Diagnosed

The only way to know whether you have OSA, CSA, or a combination of both is a sleep study (polysomnography), performed either in a sleep lab or, in many cases, at home with a portable monitor. The study measures your breathing patterns, oxygen levels, heart rate, and brain activity throughout the night.

Results are reported using the Apnea-Hypopnea Index (AHI) — the number of breathing pauses per hour of sleep — along with the type of events recorded (obstructive vs. central). Your sleep physician uses this data, along with your medical history, to determine your diagnosis and the most appropriate therapy. If you've already had a sleep study and aren't sure what your results mean, our guide to sleep apnea ICD-10 codes explains how these conditions are classified and coded.

Treatment Options for Obstructive Sleep Apnea

CPAP and APAP Therapy

Continuous Positive Airway Pressure (CPAP) is the gold-standard treatment for OSA. A steady stream of pressurized air keeps the airway open, preventing the tissue collapse that causes apnea events. Auto-adjusting CPAP (APAP) takes this further by automatically adjusting pressure throughout the night based on your real-time breathing needs. If you're trying to decide between these and other PAP device types, our full CPAP vs BiPAP vs APAP comparison breaks down every option in detail.

Lifestyle Changes

For mild OSA, weight loss, reducing alcohol intake before bed, quitting smoking, treating nasal congestion, and avoiding sleeping on your back can meaningfully reduce apnea events. These changes are often used alongside — not instead of — CPAP therapy.

Oral Appliances

Mandibular advancement devices reposition the lower jaw forward to widen the airway, and tongue-retaining devices hold the tongue in place to prevent it from blocking the throat. These are typically prescribed for mild to moderate OSA or for patients who cannot tolerate CPAP.

Surgery

Surgical procedures to remove excess tissue or reposition the jaw are generally considered when other treatments have failed. Surgery carries real risks and does not guarantee a cure — it's typically a last-resort option discussed with an ENT specialist.

Treatment Options for Central Sleep Apnea

Treating the Underlying Cause

Because CSA is so often linked to another medical condition, treatment frequently starts with managing that condition — for example, optimizing heart failure medications, adjusting opioid dosing, or addressing a neurological issue with the appropriate specialist.

Adaptive Servo-Ventilation (ASV)

ASV is a specialized device designed specifically for CSA and complex sleep apnea. It continuously monitors your breathing pattern and delivers variable pressure support to smooth out irregular breathing, preventing the long pauses characteristic of CSA.

Bilevel (BiPAP) Therapy

For some CSA and complex sleep apnea patients, bilevel therapy — which delivers a higher pressure on inhalation and a lower pressure on exhalation — provides effective support. Our CPAP vs BiPAP comparison guide explains how bilevel devices differ from standard CPAP and who they're typically prescribed for.

Medications

In select cases, medications such as acetazolamide may be used to help regulate breathing patterns, typically as an addition to device-based therapy rather than a replacement for it.

Who Should Buy What? Equipment Guidance by Diagnosis

If you've been diagnosed with OSA and prescribed CPAP or APAP, an auto-adjusting machine offers the most flexibility as your therapy needs change over time.

If you've been diagnosed with CSA, complex sleep apnea, or were prescribed bilevel support by your physician, a dedicated bilevel device is essential — standard CPAP will not provide the breathing support these conditions require.

Not sure which category you fall into, or what your sleep study results actually mean? That's exactly what a consultation is for.

Once your equipment arrives, our CPAP Setup & Education session ($75) ensures your pressure settings, mask fit, and mode (CPAP, APAP, or bilevel) match exactly what was prescribed. And if you're already on therapy and want a check-up, our Compliance Review & Data Report ($50) lets a licensed RRT review your usage data and flag any concerns.

Frequently Asked Questions

What is the main difference between central and obstructive sleep apnea?

Obstructive sleep apnea is caused by a physical blockage of the airway from relaxed throat tissue. Central sleep apnea is caused by the brain failing to signal the breathing muscles, even though the airway remains open. OSA usually causes loud snoring; CSA usually does not.

Can you have both OSA and CSA at the same time?

Yes. This is called complex sleep apnea or treatment-emergent central sleep apnea. It's sometimes discovered only after starting CPAP for OSA, when central apnea events appear or increase. A sleep physician may then recommend bilevel or ASV therapy instead.

Does CPAP work for central sleep apnea?

Standard CPAP is not the first-line treatment for CSA because it doesn't address the underlying signaling problem. CSA is more often treated with adaptive servo-ventilation (ASV), bilevel therapy, or by managing the underlying medical condition, such as heart failure.

Is central sleep apnea more dangerous than obstructive sleep apnea?

Both forms carry health risks, but CSA is frequently a marker of an underlying condition — most often heart failure — that itself requires medical attention. Neither type should be left undiagnosed or untreated. A sleep study and follow-up with your physician are essential for either diagnosis.

How common is central sleep apnea compared to obstructive sleep apnea?

Obstructive sleep apnea is far more common, accounting for the large majority of sleep apnea diagnoses. Central sleep apnea is less common and is more frequently seen in older adults and people with heart failure, stroke history, or opioid use.

Can central sleep apnea go away on its own?

It depends on the cause. CSA related to high altitude often resolves once you return to a lower elevation. CSA related to opioid use may improve if the medication is adjusted by a physician. CSA related to heart failure or neurological conditions typically requires ongoing management of the underlying condition alongside device-based therapy.

Key Takeaways

• OSA is a mechanical airway blockage; CSA is a brain signaling problem — the airway stays open
• OSA usually causes loud snoring; CSA usually does not
• OSA is far more common and is typically treated with CPAP or APAP
• CSA is often linked to heart failure, stroke, or opioid use, and is typically treated with ASV or bilevel therapy
• Some patients have both (complex sleep apnea), sometimes only discovered after starting CPAP
• A sleep study (polysomnography) and AHI results are required to distinguish between the two — symptoms alone aren't enough
• ASV is contraindicated in certain heart failure patients and requires physician oversight

Related Resources From My Respiratory Company

• Sleep Apnea: Symptoms, Causes, Diagnosis, and All Treatment Options
• CPAP vs BiPAP vs APAP: Every Type of PAP Device Explained
• CPAP vs BiPAP: Complete Comparison
• Sleep Apnea ICD-10 Codes Explained
• CPAP: Cash Pay vs Insurance — Which Saves You More?

Written by Yashil Bhatt, RRT — Licensed Registered Respiratory Therapist credentialed in Georgia and South Carolina, with ICU and critical care experience. Owner of My Respiratory Company, serving the CSRA region (Augusta GA, Evans GA, Aiken SC, Columbia SC) and patients nationwide. This article is for educational purposes and does not replace medical advice — always consult your physician or sleep specialist for diagnosis and treatment.