Health

Experts Explain What It Means When You Wake Up Soon After Quickly Falling Asleep

It’s all to do with the structure of sleep.

by Sophie McEvoy and Orla Pentelow
Updated: 
Originally Published: 
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Sleep. We all know how important it is. That awful feeling of dragging yourself out of bed when you’ve barely slept is enough evidence. But unfortunately for some, getting a good night’s sleep can be seriously elusive. Some find it hard to drift off, and others find that they can get to sleep easily but wake up after a few hours. While the latter could be down to some trivial reasons — like a loud noise or forgetting to take that last-minute trip to the toilet — it could 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?

Why does it mean if I wake up after two hours of sleep?

Alison Gardiner, who is a behavioural psychologist and the founder of Sleepstation, an online sleep improvement programme, told Bustle that, if you're trying to understand why you wake up after two hours of 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.'"

Dr Katharina Lederle, a sleep and circadian specialist who works with insomniacs through her program Somnia, agrees. “We sleep in cycles of around 90-120min,” Dr Lederle told Bustle. “At the end of a cycle we all briefly wake up, just a little to probably check the environment, roll over and then go back to sleep again. However, in times of stress, the brain can wake up fully in these moments and the thinking, planning, problem-solving, and worrying start.”

But how does falling asleep quickly factor into this? During the day, we build up a neurotransmitter called adenosine that makes us feel sleepy. “This is part of what contributes to ‘sleep drive’,” Dr Nishi Bhopal, a sleep specialist for SleepAdvisor and integrative psychiatrist, tells Bustle. “The longer you stay awake, the higher the sleep drive and the faster you fall asleep.”

Sleep is usually deepest earlier in the night, when you first fall asleep and becomes lighter as the night goes on, Dr Bhopal adds. “Once you've slept for a few hours, your brain starts clearing out the adenosine, sleep drive goes down, and you may experience lighter stages of sleep and awakenings.” However, 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 you stay awake for a long period of time or if you stay up late, you will fall asleep faster due to the adenosine level building up throughout the hours you've been awake. This is due to a phenomenon called homeostatic sleep drive, which is sometimes referred to as sleep load or sleep debt.

However, Sleep.org 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.

What is sleep maintenance insomnia?

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.”

What is 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.

What can you do to improve your sleep?

Thankfully though, if you’re struggling to get back to sleep after waking up in the night, 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]affeine 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” should help.

If you’re struggling to drift back off after waking up in the night, it could be anxieties keeping you from falling back asleep. Dr Lederle suggests trying to reduce the stressors throughout the day, too, and carving out more me-time for yourself. “At night, learn to non-judgmentally observe your thoughts and then distance yourself from them,” Lederle told Bustle. Trying meditative breathing exercises and guided meditation could help. “The key is to remain objective yet compassionate while returning to the present moment. As a result you remain calm and open. From there sleep can re-emerge.”

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 through the NHS in England and available for private purchases across the globe.

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