what causes snoring, and approx. what percentage of people snore?

Answer
What Causes Snoring?
Snoring occurs when the flow of air through the mouth and nose is physically obstructed. Air flow can be obstructed by a combination of factors, including:

—Obstructed nasal airways: Some people snore only during allergy seasons or when they have a sinus infection. Deformities of the nose such as a deviated septum (a structural change in the wall that separates one nostril from the other) or nasal polyps can also cause obstruction.
—Poor muscle tone in the throat and tongue: Throat and tongue muscles can be too relaxed, which allows them to collapse and fall back into the airway. This can result from deep sleep, alcohol consumption and use of some sleeping pills. Normal aging causes further relaxation of these muscles.
—Bulky throat tissue: Being overweight can cause bulky throat tissue. Also, children with large tonsils and adenoids often snore.
—Long soft palate and/or uvula: A long soft palate or a long uvula (the dangling tissue in back of the mouth) can narrow the opening from the nose to the throat. When these structures vibrate and bump against one another, the airway becomes obstructed causing snoring.
—Health Risks Associated With Snoring
Habitual snorers can be at risk for serious health problems, including obstructive sleep apnea. Sleep apnea creates several problems, including:

—Long interruptions of breathing (more than 10 seconds) during sleep caused by partial or total obstruction or blockage of the airway.
—Frequent waking from sleep, even though you may not realize it.
—Light sleeping. People with obstructive sleep apnea sleep lightly to try to keep their throat muscles tense enough to maintain airflow.
—Strain on the heart. Prolonged suffering from obstructive sleep apnea often results in higher blood pressure and may cause enlargement of the heart, with higher risks of heart attack and stroke.
—Poor night’s sleep. This leads to drowsiness during the day and can interfere with your quality of life.
——————————————————————————
PERCENTAGE OF PEOPLE THAT SNORE:
Most people who snore while sleeping are breathing through their mouth; the percentage is most likely 99.9% sleeping with their mouths open. When a person breathe only through their nose with mouth closed, it is much harder to make a snoring sound.

http://www.lifemana.com/stop-snoring.html

——————————————————————–
How many people habitually snore is difficult to pin down, but epidemiological surveys indicate that the number may be high, affecting an estimated 30 percent of women and 40 percent of men. Moreover, the percentage of people who snore increases as people age.

“Most snoring questionnaires depend on patients being aware of their own snoring, which may not be the case,” said Dr. Wendell G. Yarbrough, assistant professor in the division of otolaryngology-head and neck surgery at UNC. “In any event, subjective snoring often goes underreported.”

http://www.unc.edu/news/archives/sep01/snore091801.htm