WASHINGTON — Most of the United States will “fast-track” to daylight saving time on Sunday. Losing that amount of sleep doesn’t just leave you feeling tired and grumpy the next day. It may also be harmful to your health.

When it gets dark in the morning and there’s more light in the evening, our body clock gets thrown off. In other words, daylight saving time can cause sleep disturbances. Studies have even found an increase in heart attacks and strokes right after the March time change.

There are ways to make adjustments easier, like getting more sunlight to reset your circadian rhythm for healthy sleep.

“As with traveling across many time zones, travel times vary widely from person to person,” said Dr. Eduardo Sanchez of the American Heart Association. “Understand that your body is changing.”

When does daylight saving time start? It begins at 2 a.m. Sunday, erasing one hour of sleep in most areas of the United States. This ritual is reversed on November 3rd, when clocks “go back” to standard time.

Hawaii and most of Arizona, like Puerto Rico, American Samoa, Guam, and the U.S. Virgin Islands, do not make a spring changeover and maintain standard time year-round. Dozens of countries around the world also observe daylight saving time with different start and end dates.

What happens to your brain when you feel lighter later? The brain has a master clock, which is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we feel sleepy and when we feel more awake.

Morning light resets the rhythm. In the evening, levels of a hormone called melatonin begin to spike, causing sleepiness. Too much light in the evening will give you an extra hour of light after daylight saving time, delaying the light surge and causing your cycles to get out of sync.

Lack of sleep is linked to heart disease, cognitive decline, obesity, and many other problems. The circadian clock also influences heart rate, blood pressure, stress hormones, metabolism, and more.

How does the time change affect your health? A study of traffic fatalities in the United States found that there was a temporary spike in fatal car crashes in the first few days after time zone changes in the spring. Risk was highest in the morning. Researchers believe that sleep deprivation is to blame.

Then there is the heart connection. The American Heart Association points to research that suggests heart attacks increase on the Monday after daylight saving time begins, and strokes increase in the following two days. (Doctors already know that heart attacks, especially severe ones, are generally more likely to occur on Mondays, and in the morning.)