-- This Sunday, nearly everyone in the U.S. will need to set back their clocks one hour as daylight saving time comes to an end. While this means an extra hour of sleep, surprisingly it can also take a toll on health.
An extra hour of sleep can be a welcome respite for many people. But it can also disrupt normal sleep patterns, which puts strain on the body.
The change in schedule can throw off the body's internal clock, or circadian rhythm, Dr. Samuel Friedlander, assistant clinical professor of Sleep Medicine and Allergy Immunology at UH Cleveland Medical Center, said.
"It is great to have the extra hour of sleep, but a few days later that can lead to worse sleep," Friedlander told ABC News. "It can lead to insomnia or sleepiness."
As a result of disturbed sleep, Friedlander said the body is put under stress. Sleep is an important part of health.
"It affects nearly every system in the body, so that's how it can lead to problems in the body," he said.
One way to help acclimate is to get on a good sleep schedule before the time change, Friedlander said -- including any sports fans who spent last week staying up late to watch baseball.
"A lot of the nation has been up for the World Series, we are more sleep deprived than normal," Friedlander said. "Adding daylight savings time can make the situation worse."
Though the time change is coming soon, using the time before it happens to adjust sleep patterns can help.
"Try to start out having good sleep habits and get enough rest so your body can acclimate better," Friedlander added.
Once the time change happens, the sun will go down earlier and days at the end of the year are shorter. This means that people will be spending more waking hours in the dark, which leads to an increased risk of developing seasonal affective disorder (SAD).
Friedlander noted the uptick in risk as daylight saving time ends, "SAD is a very important condition that we have to watch out for."
Symptoms of SAD including fatigue, sleep difficulty or excessive sleeping, weight gain, feelings of hopelessness or despair and thoughts of suicide, according to the American Psychological Association (APA).
The end of daylight saving time also presents hazards for drivers, who will be spending more time on the road when the sun is down. The National Highway Safety Administration has cautioned "motorists and pedestrians to be more alert as the potential for harm increases as darkness falls earlier."