"This is very much in line with what I'm seeing in my practice. People in the U.S. don't make sleep a priority," said Dr. Stasia J. Wieber, director of the Comprehensive Center for Sleep Medicine at Mount Sinai Medical Center in New York City. "It really is a very important aspect of one's health care and public health. It affects your personal health and also can put others in jeopardy."

The poll of 1,500 adults was released as part of the sleep foundation's Eighth Annual National Sleep Awareness Week campaign, March 28 through April 3, which coincides with the return of Daylight Saving Time.

Sleep problems are on the rise but too often ignored, the poll found. Although half of those surveyed reported a sleep problem such as snoring or waking up during the night and 24 percent said the problems affected their daily activities, 75 percent of the respondents didn't characterize their symptoms as a sleep problem.

On average, Americans sleep 6.9 hours a night, just below the recommended seven to nine hours. But more people today say they are sleeping less than six hours on weeknights (16 percent vs. 12 percent in 1998) and on weekends (10 percent vs. 8 percent in 1998).

More than one half (54 percent) of respondents said they had at least one symptom of insomnia a few nights a week or more. The most commonly cited symptoms were waking up feeling unrefreshed (38 percent) or waking during the night (32 percent).

The repercussions of not having a good night's sleep are numerous and can be serious, even life threatening. Sixty percent of adults licensed to drive said they had driven while drowsy over the past year, the highest rate since the poll was first conducted in 1999. Four percent said they had had an accident or near accident due to drowsiness while behind the wheel. If extrapolated to the rest of the population, this would mean that about 115 million people felt tired behind the wheel while more than 7 million drivers had an accident or near accident due to sleepiness, the researchers said.

Almost one-third of working adults said they had missed work or made mistakes at work because of problems sleeping in the past three months.

The great sleep divide also takes a toll on relationships. More than three quarters (77 percent) of adults with spouses or partners said their partner had a sleep-related problem, most commonly snoring. Because of their partner's sleep issues, these respondents lost an average of 49 minutes of sleep a night -- or 300 hours a year. Nearly one-quarter of adults with partners said they have sex less often or have less interest in sex because they are so tired. One third of this group reported problems in the relationship because of their partner's sleep problems. Many sleep separately as a result of the disruption, the survey found.

Nine out 10 adults said their most popular activity in the hour before going to sleep was watching television, while only 27 percent said they had sex.

The poll also found that poor health was often associated with poor sleep. Adults with at least one common medical condition, such as high blood pressure or arthritis, are less likely to sleep well and are about twice as likely to feel drowsy during the day.

In line with other studies, this poll found that nearly two-thirds of Americans (64 percent) are overweight or obese -- and that this condition contributes to sleep problems. Compared to adults of normal weight, people who are obese are more likely to sleep less than six hours each weeknight (18 percent vs. 11 percent) and often feel sleepy during the day (37 percent vs. 26 percent).

Overweight and obese individuals were also nearly six times as likely to suffer from sleep apnea than normal-weight individuals. According to the report, more than a quarter (26 percent) of respondents were at risk for sleep apnea, a condition marked by disruptions in breathing while a person is asleep. The condition is associated with high blood pressure and stroke.

More than half the people surveyed take naps at least once a week, and one-third said they nap two or more times each week. The average duration of a nap is 50 minutes for those who nap more frequently. Sleep experts recommend naps lasting 20 to 45 minutes.

Most Americans do not use anything to help them fall asleep, although 11 percent of the poll respondents said they used alcohol a few nights a week. About 80 percent of adults said they drink at least one caffeinated beverage daily and one-quarter of those people reported consuming four or more such drinks daily. Experts recommend avoiding both alcohol and caffeine before going to bed.