When thinking about sleep and health, it’s common to focus on the issue of sleep quantity and whether we’re getting the recommended number of hours of sleep. While total sleep time is undoubtedly important, sleep continuity, or the ability to avoid interrupted sleep, is also critical.
Most people know that sleeping in stops and starts doesn’t feel as refreshing. Research studies have shown a correlation between subjective ratings of sleep quality and sleep continuity. Interrupted or fragmented sleep can contribute to insomnia, sleep deprivation, daytime sleepiness, and the numerous other potential consequences of insufficient sleep.
Knowing more about the symptoms, causes, and implications of interrupted sleep can help you be informed about your situation and find the best treatments or preventative measures to minimize your sleep disturbances.
For many people, the central symptom of interrupted sleep is easily noticeable: waking up from sleep one or more times during the course of the night (or during the day for people who work a night shift).
The timing and length of these wakeful episodes can vary. A person may have only a few breaks in sleep or several. They may be awake for just a few minutes or for an extended period before transitioning back to sleep. A person may experience restless sleep, tossing and turning or feeling only half-asleep without drifting off into deeper rest.
Not all cases of interrupted sleep, though, are readily apparent to the sleeper. Some people experience very brief and minor awakenings or arousals during the night without realizing it. For example, people with obstructive sleep apnea (OSA) have repeated lapses in breathing that cause brief arousals from sleep. These respiratory arousals are short enough that people with OSA usually don’t usually know that they are happening.
With a condition like OSA or other situations in which sleep fragmentation is frequent but not noticed by the sleeper, excessive daytime sleepiness is likely to be a key symptom of interrupted sleep.
The implications of interrupted sleep can be significant with impacts not just on sleep quality but also numerous aspects of individual health.
People who have interrupted sleep tend not to get enough overall sleep. Research has found a strong correlation between sleep continuity and total sleep time, indicating that people with disturbed sleep are at a higher risk of not sleeping enough hours. Not surprisingly, problems with sleep maintenance are a frequent complaint among people with insomnia. Insufficient sleep can cause daytime sleepiness that detracts from school or work performance and heightens the risk of accidents while driving or operating machinery.
Even when it doesn’t reduce sleep quantity, a mounting body of evidence points to the harm of interrupted sleep. During healthy sleep, a person progresses through a series of sleep cycles, each of which is made up of distinct sleep stages. Repeated interruptions and awakenings can disrupt that process, causing far-reaching effects of disrupted sleep on brain function, physical health, and emotional well-being.
Multiple studies have identified sleep continuity as important to thinking, memory, and decision-making. While the exact mechanisms underlying sleep’s role in brain health are not fully understood, research points to uninterrupted sleep as promoting memory consolidation.
Sleep disruptions have also been associated with neurodegenerative disease including age-related cognitive impairment, Alzheimer’s dementia, and Parkinson’s Disease. Fragmented sleep is considered to be an early symptom of these conditions, but research suggests that it may also be a contributing factor to their development and/or progression.
In addition, repeated awakenings during sleep have been connected to mood disorders like depression. One study demonstrated a stronger correlation between interrupted sleep and a decreased positive mood compared to reduced total hours of continuous sleep. In addition, These issues were compounded with consecutive days of interrupted sleep, suggesting that the effect can accumulate over time.
Disrupted sleep can cause detrimental impacts on physical health as well. Otherwise healthy people have been found to have higher sensitivity to pain after just two nights of fragmented sleep. The long-term inability to proceed through each sleep stage combined with the activation of multiple systems of the body during repeated awakenings has been tied to higher rates of cardiovascular disease, weight gain, and metabolic problems including type 2 diabetes. Disturbed sleep may also be connected to cancer risk, although further research is necessary to better understand the complexity of the relationship between sleep and cancer.
All of these potential effects of interrupted sleep on the brain and body indicate that healthy sleep means more than just sleeping enough hours; it also requires avoiding disruptions that inhibit sleep continuity.
There are a wide-range of potential causes of interrupted sleep, and multiple factors may be involved in any specific person’s situation.
Sleep fragmentation is often a problem for older adults because they experience a natural change in their sleep patterns resulting in less time in deep sleep. With more time in light sleep stages, they are more easily awoken, leading to a greater number of disturbances and awakenings.
Sleep disorders like obstructive sleep apnea and Restless Leg Syndrome (RLS), which creates a strong sensation to move the legs most commonly, are known to disrupt sleep. Other coexisting medical conditions, including pain, frequent urination at night (nocturia), cardiovascular issues, as well as hormonal, lung, and neurological problems may threaten sleep continuity. Prescription drugs can interfere with sleep, and complex schedules for timing and dosage of drugs may require waking up during the night to take medications.
Stress from a person’s personal or professional life may cause interrupted sleep, and anxiety, including worrying or ruminating about problems, may make it harder to get back to sleep after waking up. Parents with babies or young children can be awoken multiple times during the night, and caregivers for ill or disabled loved ones may confront similar challenges.
Changes to a person’s daylight exposure can throw off their circadian rhythm and make it hard to sleep continuously. This frequently occurs in people who have jet lag after intercontinental travel or who work the night shift and have to try to sleep during the day.
Lifestyle choices can also increase the risk of interrupted sleep. Scattershot sleep schedules, excess consumption of alcohol or caffeine, and using electronic devices like cell phones in bed can disrupt a person’s sleep patterns. Too much light in the bedroom or excess noise, including from a partner’s snoring or teeth grinding, may interfere with sleep.
If you have interrupted sleep that has been going on for a long time, is persistent, or is worsening, you should talk with your doctor. You should also consult your doctor if you have any of the following issues:
It may be helpful to use a sleep diary to keep track of your symptoms including how often you experience interrupted sleep and how frequently you have excessive sleepiness during the day.
While not all causes of interrupted sleep are under your control, there are concrete steps that you can take to try to prevent interrupted sleep before it happens or address it if you’ve already found it to be a problem.
Sleep hygiene is a general term used to describe sleep-related habits and routines along with the sleep environment. Good sleep hygiene eliminates barriers to both falling asleep and staying asleep, making it easier to get solid nightly rest without distractions or disturbances.
A core element of sleep hygiene is making sure that your daily habits work to your benefit in promoting consistent sleep. Examples of healthy sleep tips to improve your habits include:
To facilitate sleep continuity, you want to eliminate as many possible sources of sleep disturbances from your bedroom as you can:
Working with a health professional can help if your sleep is being interrupted by underlying sleep disorders or health problems. For example, treatment for obstructive sleep apnea can dramatically reduce sleep fragmentation in people with that condition, and working with a counselor can frequently improve sleep in people with mental health disorders like depression and anxiety.