From the Guidelines
Obstructive Sleep Apnea (OSA) is primarily caused by a combination of factors, including genetics, anatomical characteristics, functional traits, age, sex, body mass index (BMI), and lifestyle, as stated in the most recent study 1. The most common causes of OSA include:
- Excess weight and obesity, which create fat deposits around the upper airway that can obstruct breathing
- Anatomical features, such as having a naturally narrow airway, enlarged tonsils or adenoids, a small lower jaw, or a large tongue
- Age, as muscle tone decreases as people get older, allowing for more airway collapse
- Other contributing factors, including smoking, alcohol or sedative use before bedtime, nasal congestion or anatomical abnormalities like a deviated septum, and certain medical conditions such as hypothyroidism, acromegaly, and polycystic ovary syndrome
- Family history, which increases risk, suggesting a genetic component
- Sex, with men being more likely to develop OSA than women, though women's risk increases after menopause These causes are supported by various studies, including those that investigated the impact of concomitant medications on OSA 1, the management of OSA in commercial motor vehicle operators 1, and the role of weight management in the treatment of adult OSA 1. Additionally, a recent study published in 2025 1 highlights the importance of considering OSA as a sleep-breathing disorder that involves complete or partial cessation of breathing while sleeping due to complete or partial pharyngeal obstruction, and emphasizes the need for a multidisciplinary approach to manage OSA, including the use of mandibular advancement devices (MAD) and myofunctional therapy (MT). Overall, understanding the causes of OSA is crucial for developing effective treatment strategies that prioritize morbidity, mortality, and quality of life as outcomes.
From the Research
Causes of Obstructive Sleep Apnea (OSA)
The causes of OSA can be attributed to a combination of anatomical and non-anatomical factors. Some of the key factors include:
- Anatomical factors such as a narrowed upper airway (UA) due to inherent craniofacial anatomy, neck fat accumulation, and rostral fluid shifts in the supine posture 2
- Non-anatomical factors such as sleep-induced attenuation of UA dilating muscle responsiveness, respiratory instability, and high loop gain 2, 3
- Obesity, which is considered the main cause of developing OSA, as it leads to increased fat accumulation in the neck and throat, causing narrowing of the airway 4
- Other predisposing factors such as age, hormonal abnormalities, and decreased muscle tone 4, 5
- Mechanical and metabolic responses of the upper airway musculature, loop gain, arousal threshold, and hormonal abnormalities also play a role in the genesis of obstructive apneas 4
Anatomical Factors
Anatomical factors that contribute to OSA include:
- Upper airway collapsibility 3
- Anatomically narrow or collapsible airway 6
- Craniofacial anatomy 2
- Neck fat accumulation 2
Non-Anatomical Factors
Non-anatomical factors that contribute to OSA include: