What Really Causes Sleep Apnea? It's Not Just About Weight

By: Adam Wertz, CEO & Founder of Rebis Health

Sleep apnea develops primarily due to three interacting factors:
(1) excess weight, (2) craniofacial anatomy, and (3) impaired nasal function.

Most sleep medicine today focuses on diagnosing the presence and severity of sleep apnea. Far fewer systems ask the more important question: Why does this individual have it in the first place?

________________________________________________________________________________________________________________

What Is Sleep Apnea, Really?

Sleep apnea is a condition defined by repeated narrowing or collapse of the airway during sleep, leading to disrupted breathing, reduced oxygen levels, and fragmented sleep.

It exists on a spectrum known as sleep-disordered breathing and is most commonly expressed as obstructive sleep apnea (OSA), where airway structure and function determine whether breathing remains stable through the night.

Sleep testing, whether performed in a lab or at home, can measure how often these events occur and how severe they are.

But these tests answer what is happening, not why it is happening.

________________________________________________________________________________________________________________

The Three Root Causes of Sleep Apnea

Sleep apnea is not random. It is the predictable result of measurable forces acting on the airway.

1. Body Weight and Metabolic Load

Excess weight is the most widely recognized contributor to sleep apnea. Fat deposition within the tongue, soft palate, and surrounding airway tissues reduces airway size and increases its tendency to collapse during sleep. Even modest changes matter:

• A 10% increase in body weight can significantly increase apnea severity

• Higher BMI is strongly associated with increased airway collapsibility

And yet, weight alone does not explain everything. Not all individuals with elevated BMI develop severe sleep apnea. And many individuals with normal weight do. Which means the answer goes deeper.

2. Jaw Structure and Craniofacial Anatomy

The airway does not exist in isolation. It is housed within a structural framework—the craniofacial respiratory complex. The development of the maxilla, mandible, and surrounding skeletal structures determines the size of the airway “container.” When this framework is underdeveloped, the airway is inherently smaller and more prone to collapse.

Common anatomical contributors include:

• Retruded jaws (retrognathia)

• Narrow or high-arched palate

• Maxillary deficiency

• Enlarged tongue or soft tissue crowding

This explains a critical observation: Sleep apnea can occur in any body type because anatomy sets the boundary conditions for breathing. At Rebis, this is directly measured using 3D cone beam CT (CBCT) imaging, allowing visualization of airway volume and structural constraints—not assumptions.

3. Nasal Function and Airflow Resistance

The third domain is often overlooked but physiologically essential: nasal breathing. The nose accounts for the majority of resistance in the upper airway, meaning even small impairments can alter how air flows through the system.

When nasal airflow is restricted:

• Breathing shifts from nasal to oral

• Airflow velocity increases

• Negative pressure in the throat rises

• The airway becomes more collapsible

This creates a cascade that amplifies sleep apnea severity. Nasal dysfunction rarely acts alone—but it lowers the threshold at which collapse occurs and worsens outcomes when combined with other factors.

At Rebis, nasal function is objectively measured using:

• Acoustic rhinometry (nasal volume)

• Rhinomanometry (airflow resistance)

Because airflow is not theoretical—it is measurable.

________________________________________________________________________________________________________________

Why Most Sleep Tests Don't Give You the Full Picture

Modern sleep testing is highly effective at identifying:

• Whether sleep apnea is present

• How severe it is

But it is not designed to evaluate:

• Airway structure

• Craniofacial development

• Nasal airflow dynamics

As a result, many patients receive a diagnosis without a full understanding of the underlying drivers. This is not due to a lack of science, the research supporting these contributing factors is well established. More often, it is a reflection of how care is structured.

Insurance systems are built to:

• Diagnose conditions

• Assign severity

• Approve standardized treatments

They are not designed to systematically investigate root cause. And so, the question of why is often left unanswered.

________________________________________________________________________________________________________________

A Root-Cause Approach: The Rebis Model

At Rebis, the starting point is different.

The question is not simply:

“Does this person have sleep apnea?”

It is:

“Why does this person have sleep apnea?”

To answer that, we use a Functional Airway Core Assessment, which evaluates the three primary drivers:

1. Weight and physiology

• BMI

• Neck circumference

• Blood pressure

• Functional Labs

2. Craniofacial anatomy

• 3D-CBCT imaging of the airway

• Structural relationships of the jaws and facial skeleton

3. Nasal function

• Rhinometry (volume)

• Rhinomanometry (resistance)

This approach aligns with the understanding that airway collapse is not caused by a single factor, but by the interaction of structural and functional forces.

________________________________________________________________________________________________________________

Finding the Right Treatment Starts With Finding the Right Answer

When the cause is identified, treatment becomes more precise.

• If weight is the primary driver then metabolic intervention becomes central

• If anatomy is limiting then structural expansion or correction is considered

• If nasal resistance is elevated then airflow optimization becomes essential

This is the difference between managing a condition and understanding it. This is the difference between Rebis and everyone else. 

________________________________________________________________________________________________________________

The Question That Changes Everything

Sleep apnea is often treated as a number, a severity score on a report. But behind every number is a structure, a function, and a reason.

The real question is not:

“How severe is it?”

The real question is:

“Why is it there?”

Because once that question is answered, the path forward becomes clearer—not just to manage symptoms, but to meaningfully address the condition itself.