RENEE MONTAGNE, HOST:
As most of us know, feeling stressed can interfere with getting a good night's sleep. And that's the very thing we need to help reduce stress. Over 70 percent of people reported having trouble with sleep in a recent poll on stress in America that NPR conducted along with our partners the Robert Wood Johnson Foundation and the Harvard School of Public health. In our continuing series Stressed Out, reporter Michelle Trudeau looks at the connection between the stress we feel and the sleep we get.
MICHELLE TRUDEAU, BYLINE: Let me start with a one-liner from Woody Allen. He wrote, the lion and calf shall lie down together, but the calf won't get much sleep. And as sleep researcher Martica Hall from the University of Pittsburgh says, that about sums up the connection between stress and sleep.
MARTICA HALL: Under stressful circumstances and when people are haunted by life, they cannot sleep very well.
TRUDEAU: When you're feeling stressed, says Hall, your body marshals its famous fight or flight response, where stress hormones, such as cortisol and adrenaline, are pumped out. Your heart rate goes up. Sugar is released. More blood is sent to your brain and muscles. Hall says, it's really hard to stay asleep through all that biological activity. She's found, for example, that cortisol, which surges to deal with that deadline or cope with that car payment - it stays elevated throughout the night. So you could be sound asleep, but cortisol is constantly nudging your brain to wake up, deal with danger - real or perceived.
HALL: So daytime stress follows you into the night and disrupts your sleep.
MAREBA MACK: Typically, I wake up four to six times.
TRUDEAU: That is Mareba Mack, 42, an Air Force vet now an education specialist with the Department of the Navy.
MACK: I'm typically consumed with a thought or an idea of what I need to do, and that can be work-related or personal or just a litany of things.
TRUDEAU: And a litany of stressful events. Mack recently moved from her home in Florida up to D.C. She's also a single mother of a seven-year-old who's a special needs child with cerebral palsy. Mack feels uprooted, anxious about her daughter, worried about her work.
MACK: I'll sleep for a couple of hours, and then I'll wake. And sleep for a couple of hours, and then I'll wake.
TRUDEAU: Throughout the night, night after night. This kind of interrupted sleep, says researcher Hall, prevents a stressed person from ever feeling well-rested.
HALL: It's not like sleep is a timeout. It isn't a timeout.
TRUDEAU: All adults, stressed or not stressed - everybody typically wakes up multiple times throughout the night, very briefly - what scientists call mini arousals. The difference, Hall has discovered, is that unstressed people go right back into deep sleep in a matter of two or three seconds. But people who report feeling lots of stress - well, they're mini awakenings last much longer - sometimes many minutes longer.
CHARLES CZEISLER: My name is Charles Czeisler, and I am chairman of the board of the National Sleep Foundation.
TRUDEAU: And a leading sleep researcher at Harvard Medical School. He says, most adults need between seven and eight hours of sleep every night. Any less on a regular basis, he calls a sleep deficiency, like a vitamin deficiency. And when we're not sleeping well, that deficiency follows us right into the next day, making it hard to handle the slings and arrows that come our way.
CZEISLER: If we're not getting enough sleep that, in and of itself - the exhaustion associated with that places a physiological burden on us. And we actually are much less resilient when we're not getting enough sleep.
AMANDA: You know, it's rough.
TRUDEAU: This is Amanda. She doesn't use her last name because she's worried about her job. She's 34, the mother of a toddler and an infant, plus gets up every morning at five for a long commute to a full-time job as a social worker helping vets find housing in San Francisco.
AMANDA: It's very rough. I've missed a lot of work because of lack of sleep.
TRUDEAU: You can hear the distress in her voice. The lack of sleep, she says, makes are not only exhausted, but forgetful, moody, overwhelmed.
AMANDA: You know, there's been nights where it's literally been - I think I got maybe two hours - maybe three hours of sleep. And I wake up in my hands are shaking, and I know I can't do it.
TRUDEAU: Researchers have some practical suggestions to help. Go to bed and get up at the same time every night, even on weekends. This will entrain your brain's biological clock to release the sleep hormone melatonin - key to us getting that seven or eight hours we need. And get all of the gadgets - cell phones, computers, TVs - out of the bedroom. It's the shortwave light that these screens emit which suppresses that vital hormone melatonin. For NPR News, I'm Michelle Trudeau.