How Daylight Saving Time Affects Health

01Much of the United States springs forward on Sunday, March 9th, for Daylight Saving Time.

02Worldwide, many other countries also observe Daylight Saving Time, starting and ending, on different dates.

03The time change can leave people tired and perhaps unhappy the next day.

04But it also might even harm health.

05Some studies have found an increase in heart attacks and strokes right after the March time change.

06However, there are ways to ease the effects of the time change, including getting more sunshine.

07The light helps reset your circadian rhythm for healthful sleep.

08In the U.S., Daylight Saving Time begins Sunday at 2 o'clock in the morning.

09The time change will reverse on November 2nd, when clocks fall back as Daylight Saving Time ends.

10The state of Hawaii and most of the state of Arizona do not make the spring change.

11Those areas remain on Standard Time, along with Puerto Rico, American Samoa, Guam, and the U.S.

12Virgin Islands.

13Some people try to prepare for the change to Daylight Saving Time by going to bed a little earlier, two or three nights ahead.

14But with a third of American adults already not getting the suggested seven hours of nightly sleep, catching up can be difficult.

15The brain has a kind of clock that is set by exposure to sunlight and darkness.

16This clock, known as the circadian rhythm, is on a roughly 24-hour cycle.

17It governs when we become sleepy and when we are more wakeful.

18The rhythms change with age.

19This is one reason that early-to-rise young children turn into hard-to-wake teenagers.

20Morning light resets the rhythm.

21By evening, levels of a hormone called melatonin begin to increase, leading to tiredness.

22Too much light in the evening, that extra hour from daylight saving time, delays the melatonin increase.

23As a result, the cycle gets delayed.

24The circadian rhythm affects more than sleep.

25It also influences heart rate, blood pressure, hormone releases, and other systems.

26Sleep deprivation, or lack of sleep, is linked to heart disease, weight conditions, problems with thinking and remembering, and more.

27Deadly car crash numbers increase the first few days after the spring time change, a study of U.S.

28traffic deaths says.

29The risk of crashes is highest in the morning, it found.

30Researchers suggested sleep deprivation might be responsible.

31The time change also has a link to the heart.

32The American Heart Association points to studies that suggest an increase in heart attacks on the Monday after daylight saving time begins, and in strokes for two days afterward.

33Doctors already know that heart attacks, especially severe ones, are a bit more common on Mondays generally.

34And in the morning, when blood is more likely to clot.

35Researchers do not know why the time change would add to that Monday connection.

36But it is possible the sudden circadian change influences other issues, such as high blood pressure, in people already at risk.

37To prepare for daylight saving time, experts offer some advice.

38Slowly move bedtimes about 15 or 20 minutes earlier for several nights before the time change.

39Try to rise earlier the next morning, too.

40Go outside for early morning sunshine the first week of daylight saving time.

41This is another way to help reset your body's clock.

42Start daily activities, like dinner or exercise, a little earlier.

43This may help tell your body to start getting used to the new conditions, sleep experts suggest.

44Daytime sleeping, the drug caffeine, and light from phones and other electronic devices can make an earlier bedtime even harder.

45Americans have discussed ending daylight saving time.

46But so far, no official changes have been made.

47Health groups such as the American Medical Association and American Academy of Sleep Medicine believe it is time to end time changes.

48The groups suggest that staying with standard time year-round works better for human biology and sleep needs.

49I'm Katie Weaver.