Why Do I Wake Up At 3 A.M. Worrying? Sleep Experts Explain

For many people, waking up in the middle of the night may be an annoyingly common occurrence.

So now sleep experts have weighed in to explain why the early hours of the morning put our minds into overdrive.

Waking up in the night is something many people do. On Tuesday morning, "Why do I wake up at 3 a.m. for no reason" was a rising search term on Google, and Twitter users have gained thousands of likes by asking people if they, too, tend to wake up in the middle of the night.

Sleep is important for our bodies and minds. At a physical level it includes cell regeneration and the clearance of metabolic waste.

At the mental level, sleep is crucial to brain functions, such as encoding memory, explained Colin Espie, professor of sleep medicine at the Nuffield Department of Clinical Neurosciences at the University of Oxford.

Sleep experts such as Espie have told Newsweek that the specific time someone wakes up is not particularly significant—though around 3 a.m. in particular could be to do with a reduction in the body's drive to sleep, meaning it's easier to wake up spontaneously, Espie said.

However, sleep is not the same all through the night. It has phases and stages, some of which are lighter or deeper than others.

Around 3 a.m. may be the time at which people start to get more REM sleep—the sleep stage in which they will dream more.

"Maybe it's possible that some of this reflects waking from anxiety dreams," said Michael K. Scullin, associate professor of psychology and neuroscience at Baylor University in Texas.

Alternatively, waking up during the night worrying may be the result of activating one's "fight or flight" system, which switches the brain from sleep mode to wake mode, said Alexa Kane, a sleep expert at the Cleveland Clinic medical center in Ohio, writing in 2019.

"When this happens, your brain switches from sleep mode to wake mode. Your mind may start to race, and your heart rate and blood pressure may go up. That makes it much harder to get back to sleep."

In any case, worries on one's mind can come from a number of sources, and according to Scullin, unfinished tasks can be a significant one. "Scientists have suspected for about a hundred years now that unfinished tasks rest at a heightened level of activation in the brain until they can be completed," he told Newsweek.

"Keeping a notepad by the bedside and writing out everything on your to-do list, as well as any other worries or stressors circulating in your mind, has been shown to help," he added.

In 2018, Scullin and colleagues found that people got to sleep more quickly if they did this before going to sleep. He thinks the same principle could apply in the middle of the night too.

Espie refers to a cognitive behavioural therapy technique that he refers to as "putting the day to rest," which involves setting aside some time before going to bed to work through what's happened that day and think ahead to the next one, which could involve writing them down.

He said this "assists the brain" to work on things.

"When people wake up during the night the thing that comes to mind that may worry them is usually quite predictable," he said. "That is, something that has been happening the previous day or something that's coming up the next day."

Scullin stated that if people cannot sleep, getting out of bed for a bit might help. "If you stay in bed when you're worried then you form an implicit association between bed-worry and that just disrupts sleep further," he said.

Woman in bed
A stock photo shows a woman lying in bed looking at a clock. Experts have told Newsweek about why some people may wake up anxious. AntonioGuillem/Getty