Snoring

Snoring, or rhonchopathy, is a characteristic low-frequency, vibrating sound that occurs during sleep as air moves through a narrowed upper airway. The sound is produced by vibration of the soft tissues of the pharynx, primarily the soft palate and uvula.

Snoring is very common. While often regarded as harmless, it can disrupt the sleep of others and, more importantly, may indicate a potentially serious condition — obstructive sleep apnea (OSA, also called OSAS).

Aetiology and Pathophysiology

The physiological basis of snoring lies in partial obstruction of the pharyngeal airway, most commonly at the level of the soft palate. During sleep, the skeletal muscles throughout the body relax naturally, including those that support the upper airway patency.

This loss of tone can allow the pharyngeal walls to collapse partially in individuals with anatomical or functional predisposition. As air passes through the narrowed segment, its velocity increases, causing the surrounding soft tissues to vibrate. This vibration generates the characteristic sound of snoring.

Several factors can predispose an individual to snoring, which are generally classified as anatomical or functional.

• Anatomical factors:
  • Obesity: Excess adipose tissue accumulates in the neck and along the pharyngeal walls. This is the most important risk factor for snoring.
  • Enlarged tonsils and adenoids: The main cause of snoring in children.
  • Elongated uvula or low-positioned soft palate.
  • Craniofacial abnormalities: A small or posteriorly positioned mandible (micrognathia or retrognathia).
  • Nasal obstruction: Conditions such as a deviated septum, nasal polyps, or chronic rhinitis that force mouth breathing and promote snoring.
• Functional factors:
  • Sleeping on the back: Encourages the tongue to fall backward, narrowing the airway.
  • Alcohol, sedatives, or hypnotics: Increase relaxation of pharyngeal muscles.
  • Smoking: Causes chronic inflammation and swelling of airway mucosa.
  • Age: Natural loss of muscle tone occurs with aging.

Clinical Significance

It is important to distinguish simple snoring from snoring associated with OSA.

• Simple snoring refers to a sound phenomenon without associated apnea or oxygen desaturation. It does not disrupt sleep architecture or cause daytime sleepiness.
• Snoring associated with OSA is typically loud and intermittent. It alternates with episodes of complete silence, during which breathing temporarily stops (apnea). These episodes usually end with a sudden gasp, snort, or choking sound as normal breathing resumes. This is often accompanied by excessive daytime sleepiness, morning headaches, and elevated blood pressure.

Diagnosis begins with a detailed medical history, including information from the sleep partner, and an examination of the upper airway to identify possible anatomical abnormalities. The gold standard for diagnosing sleep-related breathing disorders is polysomnography, an overnight study that records respiratory parameters, oxygen saturation, brain activity, and heart rate.

Treatment of simple snoring focuses on lifestyle changes such as weight reduction, avoiding alcohol and sedatives, and sleeping on the side. Management of OSA-related snoring relies mainly on continuous positive airway pressure (CPAP) therapy, which keeps the airway open throughout sleep by maintaining constant positive pressure using a special device.

Differential Diagnosis

The primary clinical challenge is to distinguish harmless snoring from OSAS. Signs such as breathing pauses during sleep, restless sleep, pronounced daytime sleepiness, and hypertension should always prompt polysomnography. It is important to remember that all patients with OSA snore, but not all individuals who snore have OSA. Definitive differentiation requires objective assessment of sleep, typically via polysomnography.