Sleep. We all know how important it is, but, sadly, it can be seriously elusive for some. You may find it hard to fall asleep all together, or you may find that you drift off easily but don't stay asleep for long. Sometimes the latter can be down to some rather trivial reasons — like a loud noise or forgetting to take that last-minute trip to the toilet — but it can also be a symptom of a potential sleep disorder. So, what does it mean if you fall asleep quickly then wake up after two hours?
Alison Gardiner, who is a behavioural psychologist and the founder of Sleepstation, an online sleep improvement programme, tells me that, if you're trying to understand what's going on with your sleep, you first need to understand "the structure of sleep." "We sleep in cycles," Gardiner explains. "During these cycles, we move through different phases of sleep. The cycles tend to go like this: wake > light sleep > deep sleep > light sleep > wake. Each cycle ends with a brief period of wakefulness and this is completely normal. In fact, no-one 'sleeps through the night', that's a myth. However, good sleepers tend not to notice these brief awakenings and often report that they 'slept through.'"
And Sleep.org agrees. “Waking once or twice during the night is normal,” the site states. However, it also points out that it can be a cause for concern when you struggle to fall back asleep after an abrupt awakening. One of the main reasons is down to a condition called sleep maintenance insomnia, it states.
Sleep maintenance insomnia is categorised by Harvard Health Publishing as a person having “difficulty staying asleep, and in particular, waking too early and struggling to get back to sleep.” The condition is also found to be “more common in women than in men”, especially women who are transitioning through their midlife as it is “often a time of psychological stress.” Sleep maintenance insomnia can also be caused by other factors, as Harvard Health points out, such as “pain, depression, or a sleep disorder such as sleep apnoea.”
Sleep apnoea, also known as obstructive sleep apnoea, “is a relatively common condition where the walls of the throat relax and narrow during sleep, interrupting normal breathing,” as the NHS describes, which “may lead to regularly interrupted sleep”. This condition can be caused by several factors, including a narrow airway, nasal congestion, smoking, alcohol, and being overweight according to the NHS. While sleep apnoea can often be one of the main reasons for waking up pretty early in your sleep, conditions like insomnia can also be the reason for interrupted sleep.
But how does falling asleep quickly factor into this? If you find it easy to doze off, it’s not “technically abnormal” as Andrew Varga, M.D. told wellness site SELF. “There’s on criteria for anything too short or instantaneous for falling asleep at night. People that don’t have sleep issues should be falling asleep within 20 minutes.” But, if you’re not getting the recommended amount of sleep per night but can fall asleep quickly, it could also be a sign that you’re sleep deprived. “If we don’t get enough hours of sleep to meet our sleep needs, we will fall asleep faster,” Brandon Peters, M.D., explained to SELF.
According to Verywell Health, this is due to the “accumulation of a chemical within the brain called adenosine,” which increases the feeling of sleepiness while awake due to the “process of energy use and metabolism.” If you stay awake for a long period of time or if you stay up late, “you will fall asleep faster because the adenosine levels have increased,” which can cause “a phenomenon called homeostatic sleep drive [which is] sometimes referred to as sleep load or sleep debt.”
Thankfully though, there are many ways to combat these issues. Sleep.org suggests a restriction on caffeine after 2 p.m., and if you’re drinking alcohol to finish it two hours before you go to sleep. This is because “[c]affiene stays in your system for up to six hours, and alcohol negatively impacts your REM sleep, resulting in tossing and turning.” Turning off any screens an hour before bed also applies here and dedicating this time to relaxing and getting your body accustomed to a “routine that signals to your body and mind that it’s time for sleep.”
If you’ve done all this but still find yourself waking up in the night, just lying in bed and getting frustrated won’t help. As Sleep.org suggests, get out of bed and “[g]o somewhere quiet, keep the lights dim, and do something relaxing (such as breathing exercises or reading) until you feel sleepy.”
You may also find Alison Gardiner's sleep improvement programme helpful. Sleepstation is free on the NHS in England and available for private purchases across the globe.