Ask the Experts; July 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Vibrating structures of the upper airway cause snoring. These tissues include the tongue, soft palate, uvula, tonsillar pillars and pharyngeal walls. During sleep, muscle tone throughout the body decreases. Relaxed airway muscles can reduce the size of the airway space, limiting airflow and creating turbulence, especially when inhaling, with snoring as the result.

The reported prevalence of snoring varies and depends on the population studied and the wording of the questionnaire. For instance, data from the 1993 Wisconsin Sleep Cohort Study of 602 people showed that 44 percent of the men surveyed and 28 percent of the women snored habitually. Overall 4 percent of the men and 2 percent of the women had snoring associated with obstructive sleep apnea, a disorder involving repeated pauses or gasps in a persons breathing during sleep when the airway is obstructed. Typically the obstruction ends with an arousal - the snorer wakes briefly - leading to fragmented, less restful sleep. Obstructive sleep apnea can cause excessive daytime sleepiness, decreased attention, poor concentration and decreased energy levels. Vascular complications such as hypertension can also contribute to the disorder. The prevalence of snoring and obstructive sleep apnea seems to increase with age, especially after 65. Additional risk factors associated with snoring include weight gain, alcohol consumption, allergies, nasal obstruction, use of muscle relaxants or sedatives, and smoking (which may increase inflammation, thereby narrowing the upper airways).