WASHINGTON (Reuters) -- Dental surgeons said Saturday they have discovered why snoring can kill sometimes: It can actually cause damage to the arteries.

"When persons with sleep apnea fall asleep, their tongue falls back into their throat, blocking their airway. As they struggle for breath, their blood pressure soars," Dr. Arthur Friedlander, an oral surgeon who worked on the study, said in a statement. "We believe that this rise in blood pressure damages the inner walls of the carotid arteries lining the sides of the neck," he added. "Cholesterol and calcium stick to the injury sites and amass into calcified plaques, which block blood flow to the brain. The result is often a massive stroke."

"The calcium deposits are just the tip of the iceberg," he said. "The X-ray can't show the true size of the plaque, which is also made up of fat, platelets and other soft tissue." When a person is suffering from sleep apnea, air cannot flow in or out of the nose or mouth. Oxygen is not taken in so carbon dioxide builds to dangerous levels in the blood.

"It's like pressing a pillow over someone's face," Friedlander said.

Some other symptoms are:

Like allergies, most people are not born with a snore; they simply acquire it over a period of time almost without exception, we sleep with our mouth closed. However, as we grow, some people develop the habit of sleeping with their mouth open. This bad habit allows the jaw to relax and drop excessively during sleep time. As a result, the skin, tissue and muscles in the throat and mouth area are stretched beyond their intended range for an extended length of time (several hours each night).

Unless deliberate corrective action is taken, this condition usually last for the lifetime of the person! In most cases, this sets the stage for snoring and the possible Development of Obstructive Sleep Apnea (OSA).

Over the long term, OSA is associated with greater risk of hypertension and cardiovascular diseases. The National Commission on Sleep Disorders Research estimates that 38,000 cardiovascular deaths, due to sleep apnea, occur each year. However, OSA was not well understood or recognized by the medical community until recently, and only a fraction of OSA patients have been diagnosed and treated.