Causes of Snoring
Snoring is primarily caused by vibration of soft tissues in the upper airway during sleep, triggered by relaxation of the upper airway dilator muscles. 1 This vibration occurs when airflow meets resistance in narrowed areas of the upper respiratory tract.
Anatomical Factors
Soft Palate and Uvula: Vibration of these structures is the most common source of snoring sounds
Nasal Obstruction:
- Septal deviation
- Nasal polyps
- Hypertrophied turbinates
- Chronic rhinitis 2
- Nasal congestion
Oropharyngeal Factors:
- Enlarged tonsils and adenoids (particularly important in children) 2
- Large tongue (macroglossia)
- Elongated soft palate
- Redundant pharyngeal tissue
Risk Factors and Contributing Conditions
Obesity
- Excess weight leads to fat deposition in upper airway tissues, narrowing the airway
- Weight reduction can significantly reduce snoring frequency 3
- BMI >95th percentile for age and gender in children is associated with increased risk 2
Sleep Position
- Supine position (sleeping on back) significantly worsens snoring 4
- Gravity causes the tongue and soft palate to fall backward, narrowing the airway
- Approximately 50% of OSA patients have positional OSA, where breathing problems are worse when supine 4
Age and Gender
- More common in middle-aged individuals
- Higher prevalence in men (40% in adult men vs. 20% in adult women) 2
- Hormonal changes in women after menopause increase risk
Alcohol and Sedatives
- Relaxes upper airway muscles
- Reduces airway muscle tone and increases resistance to airflow
- Exacerbates snoring severity
Medical Conditions
- Allergic Rhinitis: Causes nasal congestion leading to increased airway resistance 2
- Obstructive Sleep Apnea: Snoring is often a symptom of OSA 2
- Craniofacial Abnormalities:
- Retrognathia (recessed jaw)
- Micrognathia (small jaw)
- Narrow maxilla
- Nasal Polyps or Tumors: Can obstruct nasal airflow
Anatomical Measurements Associated with Snoring
- MP-H (mandibular plane to hyoid bone distance): Increased distance correlates with snoring severity 5
- PNS-P (posterior nasal spine to palate): Abnormal measurements associated with snoring 5
- Posterior Airway Space (PAS): Reduced space increases snoring risk 5
Pathophysiology
- During sleep, muscle tone decreases throughout the body
- Upper airway dilator muscles (genioglossus, tensor veli palatini) relax
- Negative pressure during inspiration pulls on relaxed tissues
- Narrowed airway causes turbulent airflow
- Tissue vibration produces the characteristic snoring sound
Special Considerations in Children
- Adenotonsillar hypertrophy is the primary cause of snoring in children 2
- Obesity is a significant risk factor in pediatric snoring
- Snoring in children should prompt evaluation for obstructive sleep apnea 2
- Children with habitual snoring may have neurocognitive impairment, behavioral problems, and failure to thrive 2
Diagnostic Approach
For patients with problematic snoring, evaluation should include:
- Sleep history (preferably with bed partner input)
- Examination of nasal structures and airflow
- Oropharyngeal examination (tonsil size, tongue position, soft palate)
- Assessment of facial skeletal morphology
- Consideration of sleep study if OSA is suspected 1
Treatment Considerations
Treatment should target the specific anatomical causes:
- Weight loss for overweight individuals
- Positional therapy for position-dependent snoring
- Nasal treatments for nasal obstruction (sprays, strips, surgery)
- Oral appliances for appropriate candidates
- Surgical options based on specific anatomical findings 1
Understanding the specific cause of snoring in each individual is essential for selecting the most appropriate treatment approach.