What are the different types of sleep apnoea? 

Sleep apnoea is a condition characterized by repeated interruptions to normal breathing during sleep, which can significantly impact a person’s quality of life and long-term health. Understanding the specific type of sleep apnoea is essential for determining the most effective treatment path and managing symptoms such as loud snoring or excessive daytime tiredness. In the UK, medical professionals categorize the condition into several forms based on the underlying cause of the breathing pauses. 

What We’ll Discuss in This Article 

• The definition and mechanics of obstructive sleep apnoea. 

• Understanding the neurological basis of central sleep apnoea. 

• The characteristics of mixed or complex sleep apnoea. 

• How symptoms differ between the various types. 

• The diagnostic process used by NHS specialist sleep clinics. 

• Common treatment approaches for each classification. 

Defining the Main Categories of Sleep Apnoea 

The two main types of sleep apnoea are obstructive sleep apnoea, which is the most common, and central sleep apnoea. While both result in breathing pauses during the night, they occur for very different physiological reasons. Obstructive sleep apnoea is caused by a physical blockage in the airway, whereas central sleep apnoea relates to how the brain controls the muscles involved in breathing. 

Distinguishing between these types is a critical step in the clinical pathway. Identifying whether the issue is structural or neurological allows healthcare providers to recommend targeted interventions, such as physical devices to keep the airway open or treatments to address underlying brain signaling issues. Most patients diagnosed in the UK fall into the obstructive category, but a specialist assessment is necessary to rule out other forms. 

Obstructive Sleep Apnoea (OSA) 

Obstructive sleep apnoea occurs when the muscles in the walls of your throat relax too much during sleep, causing the airway to narrow or close completely. As the airway blocks, the flow of air is restricted, which leads to a drop in blood oxygen levels. The brain eventually senses this drop and briefly wakes the person up so they can reopen their airway, often with a loud snort or gasp. 

This cycle can happen hundreds of times a night, preventing the individual from reaching deep, restorative sleep. Common risk factors for OSA include being overweight, having a large neck circumference, or structural features like enlarged tonsils. Because the cause is a physical narrowing, treatments often focus on keeping the airway physically open using pressure or lifestyle modifications. 

Central Sleep Apnoea (CSA) 

Central sleep apnoea is a less common form of the condition where the brain temporarily stops sending signals to the muscles that control breathing. Unlike OSA, where the person is actively trying to breathe against a blockage, a person with CSA makes no effort to breathe during an episode. This is a neurological failure rather than a physical obstruction of the throat. 

CSA is often associated with other underlying medical conditions, such as heart failure or previous strokes. It can also occur at high altitudes or as a side effect of certain medications. Because the root cause is related to brain signaling, treatment frequently involves managing the primary health condition or using specialized ventilation equipment that can assist with the rhythm of breathing. 

Mixed and Complex Sleep Apnoea 

Mixed sleep apnoea involves a combination of both obstructive and central breathing pauses during a single night. Typically, an episode begins as a central event where there is no breathing effort, followed by an obstructive event where the airway collapses. This hybrid form requires a careful diagnostic approach to ensure all components of the breathing disorder are addressed. 

Complex sleep apnoea syndrome is a specific term used when a patient initially diagnosed with obstructive sleep apnoea develops central apnoea symptoms once they begin treatment with a CPAP machine. Monitoring by a specialist sleep clinic is vital in these cases to adjust settings and ensure the treatment remains effective and safe for the patient. 

Comparison of Sleep Apnoea Types 

Specific treatments for sleep apnoea, such as CPAP or mandibular advancement devices, are prescribed based on the severity and type of the condition. The following table compares the primary features of the different types. 

Feature	Obstructive (OSA)	Central (CSA)	Mixed/Complex
Primary Cause	Physical airway blockage	Brain signaling failure	Both physical and neurological
Most Common Symptom	Loud snoring and gasping	Shortness of breath on waking	Interrupted sleep patterns
Breathing Effort	High (struggling to breathe)	None (no signal to breathe)	Variable during episodes
Typical Treatment	CPAP or lifestyle changes	Treating underlying cause	Specialized bilevel devices

Conclusion 

There are several types of sleep apnoea, with obstructive sleep apnoea being the most frequent form caused by physical airway narrowing. Central sleep apnoea is less common and relates to the brain’s failure to signal breathing muscles, while mixed forms combine both issues. Effective management depends on an accurate diagnosis through a specialist sleep study to determine which type is affecting the patient. 

If you experience severe, sudden, or worsening symptoms, call 999 immediately. 

Authority Snapshot (E-E-A-T Block) 

This article provides evidence-based information on the various classifications of sleep apnoea to help the public understand the differences between obstructive and central forms. The content is authored and reviewed by Dr. Stefan Petrov, a UK-trained physician with experience in general medicine and emergency care. All information presented is strictly aligned with current NHS and NICE clinical guidelines.