What makes someone a light sleeper? Is there a way to retrain your body to not be so sensitive?
Almost all of us will experience interrupted sleep at some point in our lives, whether due to our circumstances, a sleep disorder or health condition. Interrupted sleep has been linked to cognitive issues, neurodegenerative disorders, poor work performance, and negative consequences for our physical health and emotional wellbeing.
A 2010 study also found that for depression and anxiety sufferers, interrupted sleep causes higher rates of healthcare utilisation and higher costs of healthcare.
Given how prevalent interrupted sleep is and how serious the consequences of it can be, it’s worth investigating the symptoms, causes and impacts of interrupted sleep, as well as what we can do to address it.
What is interrupted sleep?
Waking up during sleep is normal, but waking too often or for too long can result in fragmented and poor quality sleep. It is typical to wake up at the end of each sleep cycle (every 90–120 minutes in adults) and oftentimes awakenings are so brief that we don’t even recall them.
If awakenings are excessive in frequency then this could be a sign of obstructive sleep apnea (OSA). If awakenings are excessive in duration then this could be a sign of insomnia. The amount, timing and length of awakenings can vary widely. Sometimes they are so brief that sufferers only realise that there is a problem because they experience excessive sleepiness during the daytime.
What causes interrupted sleep?
The following is a list of just some causes of interrupted sleep…
· Natural changes in sleep patterns as we age result in lighter sleeps, making older adults more susceptible to being woken during the night;
· Medical conditions including pain, frequent urination at night, cardiovascular issues, hormonal, lung and neurological problems;
· The side effects of prescription drugs;
· Stress and anxiety;
· Caregiving responsibilities;
· Changes to daylight exposure can confuse the circadian rhythm and make it harder for people to sleep continuously (e.g. jet lag or night shifts);
· Inconsistent sleep schedules;
· Consumption of alcohol or caffeine;
· Use of electronic devices in bed;
· Too much light in the bedroom;
· Intrusive noise in the bedroom, including partners who snore or grind their teeth.
What are the impacts of interrupted sleep?
Interrupted sleep is often correlated to less total sleep. As a result, night wakings may leave you experiencing daytime sleepiness. This can result in lower performance at work or in school and higher risks of causing accidents while driving or operating machinery.
Although there can be a relationship between interrupted sleep and less total sleep, it is important to recognise that interrupted sleep is a problem in and of itself, even if the total amount of sleep is sufficient. For example, a person may sleep for 10 hours each night but that sleep is so fragmented that they still don’t feel rested.
Night wakings interrupt our progression through sleep cycles and the various stages of sleep within those cycles. This can result in effects on (a) brain function, (b) physical health, and (c) emotional wellbeing.
(A) Brain function
Studies have shown that night wakings negatively impact our neurological processes including our ability to think, memorise and make decisions. Unsurprisingly, the cumulative effect of night wakings is an increased risk of developing and worsening neurodegenerative diseases including age-related cognitive impairment, Alzheimer’s dementia and Parkinson’s Disease.
(B) Physical health
The continuous inability to complete each stage of sleep and activate the corresponding bodily functions has been linked to cardiovascular disease, weight gain and metabolic problems like type 2 diabetes. In one study, participants experienced higher sensitivity to pain after just 2 nights of interrupted sleep.
(C) Emotional wellbeing
Interrupted sleep has been connected to mood disorders like depression, with the impact compounding over time. As mentioned above, one study also found that interrupted sleep worsened the condition of those suffering from anxiety and depression.
Not all causes of sleep interruptions are under our control. However, you’ll be pleased to know that there are a number of ways to improve your ‘sleep continuity’ — that is, your ability to avoid sleep interruptions — as well as the amount of ‘deep sleep’ you attain.
How to improve sleep continuity
By making simple and practical improvements to our sleep hygiene, we can achieve significant gains in regards to both staying asleep and falling asleep in the first place. Sleep hygiene refers to everyday activities and behaviours and features of our environment that we can tweak to get a better night’s sleep.
Habits that you can introduce include going to bed and waking up at the same time every day, giving yourself about an hour to wind down and relax before going to bed, and avoiding alcohol, cigarettes, caffeine and large or spicy meals in the evening.
Changes to your sleep environment could include using a sleep mask, ear plugs or a white noise machine, lowering the temperature of your bedroom and using comfortable bedding.
For more tips on how to improve your sleep hygiene, check out our article dedicated to that topic.
If improvements to your sleep hygiene don’t work, doctors can prescribe treatment plans. For chronic insomnia, sleep hygiene improvements will not usually suffice, but cognitive behavioural therapy for insomnia (CBT-I) is highly effective. In patients with obstructive sleep apnea, treatments have dramatically reduced sleep interruptions. Alternatively, counselling has proven successful in treating interrupted sleep associated with mental health conditions such as depression or anxiety.
You should seek the attention of a healthcare professional if…
· Sleep interruptions continue for a long time or worsens; or,
· You experience significant sleepiness or mood changes during the day, snoring that is loud or involves gasping or choking, or other abnormal breathing.
By keeping a sleep diary, you can keep track of how your symptoms develop. You should take note of the frequency, timing and length of wakings.
How to sleep deeper
Interrupted sleep is often associated with people who are described as ‘light sleepers’. Whilst it is true that night wakings can be caused by lighter sleep, it is also apparent that night wakings can result in less deep sleep.
Deep sleep (or ‘slow-wave sleep’) is the stage of sleep in which slow brain waves are recorded by an electroencephalogram. Deep sleep is vital for consolidating new memories. It particularly affects our conscious recollection of factual information and experiences.
Deep sleep allows the brain to restore itself, but it is also key to many bodily functions. For example, growth hormones are secreted at their highest level during this stage.
If you wake up from a deep sleep, whether due to a night waking or your morning alarm, your mental performance is likely to be impaired for up to 30 minutes. Therefore, it’s really important that we are able to transition through the different stages of sleep by avoiding disturbances.
It is also likely that after a period of sleep deprivation, your sleep will include more and deeper deep sleep. This is because the amount of deep sleep is primarily determined by the amount of preceding wakefulness.
One way of increasing your deep sleep is to ensure you get enough total sleep each night. Check out our article on appropriate sleep duration for your age group.
Another option is to increase the amount of vigorous activity you engage in during the day. Intense, prolonged exercise involving aerobic activities like jogging, running and swimming can increase deep sleep.
Healthy eating is also key to getting more deep sleep. Studies have shown that lowering your carbohydrate intake, even for short periods, promotes more deep sleep.
In summary, the best way to address interrupted sleep is by improving your sleep hygiene or seeking treatment from your doctor, and the best way to increase your deep sleep is by maintaining a consistent sleep schedule, obtaining an adequate amount of sleep, engaging in more vigorous physical exercise and eating a healthy low-carbohydrate diet.
