Between 50 million and 70 million Americans have some sort of sleep disorder, be it apnea, insomnia, narcolepsy.
And this time of year - with shopping overload, overbooked calendars and end-of-the-year work demands - can be a sleeper's nightmare.
"There just does not seem to be enough time to shop, attend holiday parties, decorate the house, work and sleep," says Mary Battaglia, 42, a co-founder of the sleep-aid company BedtimePlace.Com. "I try hard to get the right sleep because I know how important it is. But that does not always happen."
A 2005 National Sleep Foundation report found that 16 percent of 1,500 respondents said they slept fewer than six hours a night, up from 12 percent in a 1998 survey.
Adults should strive for eight hours; children and teens for nine hours. Only 26 percent reported getting the necessary eight hours, down from 35 percent.
The result: more illnesses, a weakened immune system, impaired judgment - not to mention crankiness, depression and other ailments. Recent studies have linked inadequate sleep with obesity, heart disease, high blood pressure and type 2 diabetes.
"Nothing good happens under sleep deprivation," says Joyce Walsleben, an associate professor of medicine at New York University's School of Medicine. "We're cutting sleep too short, we get irritable, get sick. Those two weeks leading into the holidays should be spent focusing on getting eight hours of sleep."
If not, problems can ensue, exacerbated by the season's higher stress levels and increased festivities. Consider:
Cases of "drowsy driving" - that nagging feeling of fighting sleep or, worse, falling asleep while driving - can be common at this time of year. Indeed, 20 percent of all serious car crash injuries are associated with driver sleepiness, according to a 2006 report from the Institute of Medicine.
"Factors that take place during this time of year make us more concerned," says Darrel Drobnich, chief executive of the Washington-based National Sleep Foundation. "College kids are doing finals and packing and staying up late to drive long distances to be with family for the holidays. Families are staying up late to pack and head out early in the morning to visit grandma and grandpa several states away. ... Office parties. Travel. People are stressed out doing Christmas shopping. It can be a hectic time of year."
The 2005 foundation poll found that 61 percent of respondents reported that they had driven while drowsy, a 14 percent increase over the previous year.
Alcohol hits us harder when we are sleep-deprived, acting in the same deleterious way as drinking on an empty stomach.
"One beer on four hours of sleep can interact like a six-pack," says Drobnich. "Sleep deprivation and low doses of alcohol increase sleepiness and crash risk. You have to be careful if you only have a couple hours of sleep and you are invited out for one holiday drink. 'I'm OK, I'm not too drunk to drive, I only had one.' But it does increase your impairment."
A lack of sleep causes the body to produce more of the hunger-inducing hormone ghrelin and less of the appetite-suppressing hormone leptin.
"When we sleep too little our brain is deprived of glucose and we try to fill it the following day," said Walsleben. "After a bad night we might increase our appetite and the body wants sugar. We're stuffing our face with cookies, the body is craving sweets."
And with holiday treats scattered around offices and parties, that means a higher risk of gaining weight.
Lack of sleep spikes levels of cortisol, the stress hormone, during the afternoon and evening when you should be unwinding, according to a 2006 University of Chicago study. The long-term risk is heart disease, hypertension and type 2 diabetes.
"I think we have to become aware that sleep is valuable, just like water," says Walsleben. "We wouldn't give up food and water - so why sleep?"
Tips for a good night's rest
Dark is good. Darkest is best. Light signals the brain to wake up. That means your alarm clock flashing those blue digits can jolt you awake long before you are ready. Turn the clock toward the wall or hit the dim switch. "You need darkness, quiet and comfort to sleep -- and the need to be safe. If you're not safe with your home or bed partner, you won't sleep well," cautions Joyce Walsleben, a sleep specialist with the New York University School of Medicine.
Eat properly. Going to bed overstuffed, especially on carbs and fat, interferes with sleep. Starving yourself also counters a good night's rest. Try a small high-protein bedtime snack, maybe a little cheese or a hard-boiled egg.
A snoring bedmate. Suggest, lovingly of course, that your partner sleep on his or her side. Barring that, opt for comfortable earplugs or consider separate bedrooms.
Keep to a schedule. Body rhythms matter. Try to wake up at the same time every day -- even if you go to bed later than usual on a party night. You might get away with sleeping in an extra hour, say on the weekend, but any more than that and you are "jet-lagging" your system.
Go to bed 15 minutes earlier. If you cut 15 minutes off your activity and go to bed at 11:45 instead of midnight you net an additional 1 3/4 hours of sleep per week. It adds up.
Nap smart. A short siesta, about 20 to 30 minutes in the early afternoon, can be refreshing. Be careful. Nap too long and you enter REM sleep. You'll wake up groggy and have a hard time falling asleep at bedtime. Napping too late in the afternoon, at 5 p.m. or later, also affects night sleep.
Keep your feet covered. This widens blood vessels down there, drawing heat from the core to the extremities, which cools you a little, inducing sleep.
Play music that you consider relaxing. Dock your iPod into a speaker system and set its timer so the lullaby can cease once you reach sleep.
Can't sleep? Stay in bed. No, get outta bed. Experts differ on this one. A Duke University expert suggests leaving the bed. Walsleben, however, advises staying in bed. "You'll have more of a chance to fall asleep in a dark room than if you get up to do something else, like getting hooked on the Internet." Both agree that whichever option you settle on, do not turn on any lights.
[Sources: Darrel Drobnich, National Sleep Foundation; Joyce Walsleben, NYU School of Medicine; Drs. Dalia Lorenzo and Douglas Wallace, University of Miami Veterans Affairs Hospital; Prevention magazine; Jose Oliveros, North Shore Medical Center in Miami; National Center on Sleep Disorders Research and Institute of Medicine.]