When you wake up in the middle of the night, why don’t you check your phone and the time?
I slept well, but suddenly woke up in the middle of the night. I drowsily touched my phone and realized it was only around 3 a.m., then I tossed and turned and couldn't fall asleep anymore...I started thinking: "How many hours can I sleep if I fall asleep now?" Many people may have encountered this situation, and what's even more confusing is that some people will find that they wake up at almost the same time for several days in a row.
Why does this happen? Does your body really wake you up "on time"?
In fact, waking up in the middle of the night does not necessarily mean there is a problem with your sleep. However, there is something that many people are used to doing that may make it more and more difficult for you to fall asleep again - waking up in the middle of the night and checking the time.
take a look at the time
Why did you ruin the rest of the night?
It only takes 3 seconds to look at the time, but the psychological processes triggered by those 3 seconds are the real cause of insomnia. When you see 3:17, what your brain does is not continue to sleep, but starts calculating: How many hours are left until you wake up? Been in bed for how many hours? If I can only sleep for 3 more hours, will tomorrow be a waste?
This accompanying perception of frustration activates the body’s stress systems—sympathetic activation, increased heart rate, and elevated cortisol—the exact opposite of what is needed to fall asleep. Sleep only occurs when the nervous system is stable. The harder you try to fall asleep, the more insomnia will occur.
In one experiment, insomniac subjects were assigned to one group staring at a clock and the other at a digital display. It was found that people who looked at the clock had more sleep distress and took longer to fall asleep. It was also found that people who looked at the clock tended to overestimate how long they had been awake. Looking at the clock when you can't sleep is excruciating—suggesting that looking at the clock distorts time perception. In a study at the Stanford Sleep Clinic, patients with clock-watching insomnia overestimated sleep onset latency (the time it takes to fall asleep) by an average of 30 minutes and underestimated total sleep time by 1 hour.
The more I can't sleep, the more I want to check the time. Sleep medicine calls this behavior of repeatedly checking the time "time monitoring behavior." In 2007, Tang and Harvey of Oxford University published a study with a very disturbing name - "Sleeping with the enemy" (Sleeping with the enemy). The "enemy" in the title refers to the bedside clock.
Worry about sleep will cause people to constantly scan the clock as a "threat signal". The more they look at it, the more anxious they become, and the more anxious they become, the more awake they become, forming a vicious cycle. If you check the time on your mobile phone and scroll through Moments and short videos, then the whole night is indeed wasted. In 2023, Indiana University's Spencer Dawson team published a study on 4,886 sleep outpatients in the "Primary Care Companion for CNS Disorders" and found that the more people who check the time in the middle of the night, the more severe their insomnia and the higher the proportion of taking sleep aids.
Why do I always wake up at the same time?
It's really not "evil"
Many people have had this "evil" experience: for a week or even a month, they wake up at the same time every morning, with an error of no more than a few minutes, which is more accurate than an alarm clock.
There really is an alarm clock in the human body.
Normal human sleep lasts about 90 minutes for a complete sleep cycle. Each cycle includes light sleep, deep sleep and rapid eye movement sleep, which cycle throughout the night. Deep sleep accounts for about 20% of the total sleep time, mostly concentrated in the first 2 to 3 sleep cycles in the first half of the night. It is a critical stage for body repair and energy recovery. In the second half of the night, deep sleep is greatly reduced, and light sleep and dreaming rapid eye movement sleep are dominant, and sleep becomes lighter overall. At this time, brief awakenings are more likely to occur during sleep cycle transitions.
The secretion of the body's "stress hormone" cortisol also follows a strict circadian rhythm: it reaches its lowest level around midnight, and begins to quietly climb in the second half of the night to prepare for early morning awakening, so awakenings are more likely to occur at three or four in the morning. An experiment published in "Nature" in 1999 gave the answer: If a subject thinks about "what time will I wake up" before going to bed, the adrenocorticotropic hormone in the blood will increase significantly about an hour before the scheduled time. Multiple surveys show that more than half of the respondents can wake up independently without an alarm clock, with an error of only ten minutes.
Another mechanism of "waking up at a fixed point" is conditioned reflex. If you wake up at three o'clock in the morning several times, your brain will bind "three o'clock" and "wake up" together to form a conditioned reflex, which sleep medicine calls "conditioned arousal." If you look at the time every time you wake up, it is equivalent to giving a knife to insomnia and continuously strengthening this conditioned reflex.
I can't help but look at the time
What to do?
Studies have found that people with insomnia can't help but check the time, and this is involuntary. Just like a person who is afraid of dogs, he will stare at the dog when he sees it from a distance, because the brain has marked the "clock" as a threat signal. Looking at the time gives the illusion that "I am in control."
But in fact, I may not be able to control anything, I just feel more awake as I look at it. Normal people will feel sleepy when they see a bed, because bed and sleep have been paired countless times. For people with insomnia, the bed and the clock always appear together with "tossing and irritating" - over time, just seeing them will automatically cause anxiety.
If you can't control the time, you can try the following methods to solve the problem:
1. The simplest and most effective method is physical isolation. Don’t put an alarm clock in the bedroom, take off your smart watch, and don’t bring your phone into the bedroom.
2. Physical isolation is only the first step. People who want to look at the time will wonder what time it is now? If the anxiety is not resolved, the urge to check the time will always be there. So stimulus control is needed to reconstruct sleep-related associations and address catastrophic cognitive patterns. If you feel like you haven't fallen asleep for about 20 minutes after waking up (evaluate based on your feeling, don't look at the clock), get up and do something boring in a dark environment, and then go back to bed when you feel sleepy. The bed is only for sleeping, not for "trying to sleep". This is one of the standard behavioral therapies recommended by the American Academy of Sleep Medicine (AASM) guidelines.
3. Set a fixed wake-up time. No matter how poorly you slept the night before, wake up at the same time every day. A stable wake-up time is the strongest signal to calibrate the biological clock, and can also gradually break down the conditioned reflex of "fixed-point awakening".
4. Cognitive subtraction. Give up the obsession that you must get eight hours of sleep. Normal people will wake up briefly several times every night, and most of them will not remember it at all. It doesn't matter if you wake up in the middle of the night occasionally, and there is no need to panic too much.
5. Manage your own stress and learn to relax. Abdominal breathing and progressive muscle relaxation can reduce physical arousal levels.
If insomnia is frequent and significantly affects your daytime state, it is recommended to seek help from a professional sleep medicine doctor.
