If worries about family, money, work, or health are keeping you awake at night, you’re not alone. People in bedrooms throughout the U.S. are missing out on sleep because of those same concerns, according to a poll published this week by the National Sleep Foundation (NSF). It found that 30 percent of Americans are getting fewer than six hours of sleep a night.

The survey looked at the sleep habits and attitudes of four ethnic groups: Asians, blacks, Hispanics, and whites. More than one-third of Hispanics (38 percent) and blacks (33 percent) reported that concerns about health, finances, and personal relationships disturbed their sleep at least a few nights of the week, compared to one-fourth of whites (28 percent) and Asians (25 percent).

In our 2008 sleep survey of 1,466 adults, high stress levels stood out as the most prevalent cause of sleep problems. And like the NSF survey, most of the time respondents were anxious about family or money concerns, health issues, or work woes.

Lack of sleep can affect your overall health, so experts recommend seven to nine hours of sleep a night. But it's not just how much you sleep that counts. Some people get eight or nine hours but don't feel well-rested because of poor-quality sleep. That can leave you feeling less energetic, hinder your ability to think properly and respond quickly, affect cardiovascular health, and make it more difficult for your body to fight off infections.