At its most benign, it sounds like sawing wood. At its loudest, it has been measured at 87.5 decibels -- equivalent to a pneumatic drill pulverizing a Washington sidewalk. At its most obnoxious, it has rattled windows and destroyed marriages. At its most dangerous, it has killed people.

To most people, snoring is funny, perhaps because it seems so commonplace, a first cousin to breathing. After all, cats, dogs, elephants, mules and even American presidents have been known to snore. Several of the latter were, in fact, certifiable snoring legends: both Adamses and both Roosevelts, as well as Lincoln, Fillmore and Taft. Teddy Roosevelt's snoring once so disturbed a hospital where he was being treated for an unrelated medical ailment that every other patient filed a complaint.

Is this amusing? Not to me.

The reason: I've been both victim and the victimizer. As victim, I traveled for three years with my best friend doing research for our co-authored guidebooks to America's beaches. Though this was a dream assignment, at times it seemed more like a nightmare. Whenever we shared a motel room, which was most nights, I lost sleep to his beastly nocturnal roars.

I tried everything from Kleenex in the ears to burying my head under a wall of pillows, once even sleeping on the floor of the bathroom with the fan on. I threw pillows at my friend, shook his bed, yelled at him, prayed for relief ("If you make him stop snoring, Lord, I'll . . ."). Nothing seemed to work.

Imagine, then, my horror when I was informed recently by my girlfriend that I, too, snore. She described it as "a constant grumbling test pattern," whatever that might mean.

What's going on here?

Physiologically, snorers have a problem with abnormal airflow through the nose and throat that creates vibrations of tissue made up of the soft palate (the posterior muscle on the roof of the mouth), the uvula (a soft, fleshy cone that hangs down from the palate) and the pharynx (the tube that connects the mouth to the esophagus). Any additional structural abnormality -- a deviated septum, enlarged tonsils -- can contribute to it, although snoring is most often activated by obesity and/or age, which brings with it a flabbiness of the throat tissue. Thirty percent of the population under age 40 snores, according to the National Institutes of Health, while 50 percent over age 60 does. Most are men.

Snoring is not just a bunch of hot gargled air, either. Sometimes, in the case of chronically loud and disruptive snoring, it can mean a severe health problem. The most serious and common is sleep apnea, in which the victim actually stops breathing for intervals of 10 to 90 seconds or longer. These episodes can happen as many as 500 times a night and are often accompanied by body spasms and arm-flailing.

"There is a continuum from benign snoring to sleep apnea," says otolaryngologist Jeffrey Hausfeld, director of the sleep disorders center at the Washington Hospital Center. Hausfeld calls apnea a hidden killer, misunderstood by the millions of Americans who suffer from it and sometimes misdiagnosed by other doctors.

"During apnea, the back of the throat simply buckles up like a straw," says Hausfeld. "Usually, there is enough space between the uvula and the throat for air to get through, but any obstruction of this path can increase air pressure when the person inhales. This causes the surrounding soft tissues to pull together, completely blocking the air flow. The most common scenario is for the blood oxygen to drop, blood pressure to increase and the brain to send a wake-up message."

The next day, the apnea victim feels unaccountably sleepy. "If a person is aware that they snore and they also regularly experience daytime sleepiness, then it is a problem," says David Fairbanks, a member of the Ear, Nose and Throat Medical Group in Washington, and board adviser to Sibley Hospital's sleep disorder center. "That (daytime sleepiness) is the No. 1 indicator of obstructive sleep apnea."

According to Fairbanks, apnea of any intensity can exacerbate preexisting cardiovascular and pulmonary conditions. Hausfeld cites statistics gathered from otolaryngologists from around the country indicating that more than 3,000 Americans will die in their sleep this year of apnea, either suffocating or causing failure of a chronically weakened heart.

If apnea doesn't kill you, it can have a debilitating effect on your sex life and mental health. Prolonged snoring robs people of valuable REM (rapid eye movement) sleep, the deepest state when most dreaming takes place. It can ruin marriages, sending spouses to separate bedrooms and curtailing vacations.

"I've saved many marriages in my office," says Hausfeld. "Once the wife banishes the husband from the bedroom, they both end up here." When that happens, Hausfeld examines the snorer to determine the extent of blockage, manipulating a long, thin fiberoptic telescope through the nasal passage into the throat.

When snoring is benign, that is, some air is getting through, Hausfeld recommends less radical measures. Weight loss and physical activity are high on his list, as is avoidance of alcohol, caffeine, cold medicines and food several hours before bedtime. He also suggests that the person who doesn't snore go to bed first and that the one who does sleep on his side, his head elevated by pillows.

"There are over 350 antisnoring devices in the Patent Office," says Hausfeld. "But 99 percent work by keeping the snorer awake." In Fairbanks's opinion, "these gadgets are a sad testimony to the desperation of people suffering from snoring." For mild and occasional snorers, he recommends a whiplash collar to elevate the chin and keep the throat open or an antisnoring pillow that contains a noise-activated device that sends electronic messages to the sleeper when he snores.

When these don't work, Hausfeld sometimes recommends surgery to those patients he feels are "good candidates." The most common surgery he performs is called uvulopalatopharyngoplasty, or UPPP. UPPP is plastic surgery of the uvula, palate and pharynx, which removes the tissue responsible for snoring. He has performed 500 of these operations, combined with whatever other structural work may be needed, from resetting broken noses to removing tonsils. The UPPP, according to Hausfeld, takes two hours, followed by a week of recovery, and is 90 percent effective.

One recent UPPP patient, a member of the D.C. police SWAT team, consulted him at the behest of his girlfriend, a nurse worried about his erratic sleeping habits. He'd had his nose broken in a karate tournament 15 years ago, and his abnormal breathing led to apnea. Despite reservations, he agreed to the plastic surgery, completed last December. "I'd do it all over again," he said, "I can breathe again and sleep well, which means I'm more alert the next day at work, where things can get tense."

Luckily for me, my own snoring is mild by comparison. A pair of earplugs cured the problem for my girlfriend; fear of surgery cured it for me. Lately, she says, I am sleeping as quietly as a mouse.

Alan Bisbort is a writer in Arlington.