Sleep Archive

According to an estimate from the Institute of Medicine, up to 20% of all motor vehicle crashes are related to drowsy driving. A panel of experts recently concluded that anyone who has slept less than two hours in the previous 24 hours is not fit to drive. This is only a rough guideline, however, because the relationship between sleep and safe driving is complex. (For example, a pre-existing sleep debt and driving at night increase the effects of drowsiness.) In general, driving while sleep-deprived is a dangerous undertaking for you — and others on the road with you.

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Research we're watching

People who sleep too much or too little may be more likely to have early signs of heart disease, according to a study of more than 47,000 apparently healthy young and middle-aged adults.

The study volunteers filled out sleep questionnaires and underwent tests to assess the arteries in their hearts and legs. Researchers found that people who slept for nine or more hours per night had more calcium buildup in their heart artery walls and stiffer leg arteries than those who slept seven hours per night. These early signs of heart disease were also more prevalent in people who logged five or fewer hours of sleep per night and in people who reported poor sleep quality.

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Do you worry yourself awake frequently? Cognitive behavioral therapy can help.

If you have trouble getting to sleep and staying asleep, that's insomnia. It happens to everyone from time to time. But it can also become a chronic problem. For some men, fretting about whether they will be able to sleep—and the emotional upset of not being able to when they try—can itself become the root cause of insomnia.

Almost everyone suffers from trouble sleeping at one time or another. Insomnia — defined as trouble falling asleep or staying asleep — isn't a single disorder itself, but rather a general symptom, like fever or pain.

Because insomnia is so common, you can walk into any drugstore and find a bewildering variety of over-the-counter sleep products. And people are buying them. One small survey of people ages 60 and over found that more than a quarter had taken nonprescription sleeping aids in the preceding year — and that one in 12 did so daily.

Recent news reports of a study of sleep duration in geographically isolated societies in Africa and South America suggest that Americans are actually getting plenty of sleep because members of these tribes spend about the same amount of time asleep each night as people in modern societies. These controversial findings will be debated, but are not relevant to the widespread sleep deficit and associated health consequences in more modern societies.

Americans are sleeping less and weighing more. Science tells us this is no coincidence. Inadequate sleep can contribute to weight gain in several ways, including altering levels of the hormones that control appetite and fullness and setting off a chain reaction of poor habits that can increase the risk of weight gain and obesity. Sleep is proving to be as important to health as good nutrition and regular exercise.

Repeated nocturnal bathroom calls are bothersome, but self-help steps and targeted treatment offer relief.

Do the long hours in the hospital, often with little sleep, make doctors in training more prone to making mistakes? Over the past decade, concerns regarding trainee doctors’ sleep loss and the potential for medical errors have brought about limits on the number of consecutive hours a resident can work in the hospital. Do the same concerns apply to fully licensed surgeons? A recent study in The New England Journal of Medicine suggests that the answer is no. Comparing the data on patients whose surgeons were on call the night before with that of patients whose surgeons were not working the night before showed virtually no difference in how well the patients did after surgery. It is not clear, however, whether these doctors anticipated the effects of being on call and compensated for them, or whether these results would be the same for less-experienced surgeons-in-training.