Conditioning (conscious or unconscious)
As said above, circadian rhythms are powerful, but malleable, meaning that they will adjust to different stimuli when presented with those stimuli regularly and consistently. You may notice this during daylight savings, or if you change the time of your alarm in the morning. Even though you’ve set your alarm for, say, an hour later, your body might wake you up at exactly the time of your old alarm.
In this way, people who regularly wake up at the same time each night may be responding to some sort of prior conditioning. Cleveland Clinic suggests the example of waking to feed a baby for a period of months. The child might now be sleeping through the night and so the task may be no longer necessary—perhaps you’ve returned to a regular sleep pattern since. Despite this, your mind may be reactivating that period of conditioning for an underlying psychological reason.
Being woken during light-sleep stages
When circadian rhythms do their job and we fall asleep, we begin to cycle through 5 sleep stages. The most famous of these stages is stage 5: Rapid Eye Movement (REM) sleep. In this stage, the brain becomes more active while your muscles relax and are paralyzed by the subconscious mind, according to Psych Central. This is also when most dreaming occurs. To prolong REM sleep, try out these tips.
While stage 5 is a deep sleep from which it can take some time to wake up, stages 1 and 2 of the sleep cycle are much lighter. During these stages, you can be easily roused, especially if there’s some kind of stimuli in the environment. Therefore, one possible reason for waking at the same time every night is that, with a regular bedtime, you may be cycling through stage 1 or 2 of sleep at a certain point in the night and waking up.
Similarly, a loud noise of change in the environment might be coinciding with you entering one of these lighter sleep stages.
Is there something more ‘unnatural’ waking me up?
For reasons undoubtedly too complex for this post, there is a cultural association between waking at specific times of the night and the presence of spiritual, cosmic, or ghostly phenomena. Obviously, these theories are unsubstantiated, and while they might be interesting, they are probably not worth spending too much time thinking about.
However, for those curious, here are some of the most common spiritual or supernatural explanations for why you might repeatedly wake up at the same time:
- According to the Times of India, waking regularly between 11 pm and 1 am signifies the energy meridian of the gall bladder. Apparently, this meridian is also associated with emotional disappointment.
- Bustle reports that regularly waking between 3 and 5 in the morning signals the presence of a higher power with a message of warning. This idea, derived from traditional Chinese medicine, claims that this time frame is connected to the respiratory system, with the lungs tied to sadness, depression, and not wanting to inhale emotionally. More realistically, perhaps this idea is drawing upon the way that stress can disrupt our natural circadian rhythm.