America's adults average 6.9 hours of sleep each night, slightly less than the range of 7-9 hours recommended by many sleep experts. Three-quarters of America's adults, (75%), said that they frequently experience at least one symptom of a sleep problem in the past year. More than three-quarters of America's partnered adults (77%) say their partner has a sleep-related problem; the most common problem is snoring. One quarter of America's adults, 47 million people, don't get the minimum amount of sleep they say they need to be alert the next day. One-quarter of America's adults say their sleep problems have some impact on their daily lives. People who are already hypertensive may increase their risk of heart attack or stroke if they fail to get adequate sleep. Effects of insufficient sleep on blood pressure in hypertensive patients: a 24-hour study. Shift workers are 30-50% more likely to develop heart disease than day workers in the same industry. More than one-half of America's adults nap at least once a week.