Sleep Stages, Snoring, Restlessness
Updated: Oct 8
Sleep researchers break sleep into four parts namely N1, N2, N3, and REM. While N1 and N2 combined make up the Light sleep, N3 is referred to as deep sleep. Here how each of them is defined and why they are important.
Light sleep is an intermediate or transient stage between Deep and REM stages of sleep. It accounts for almost half the sleep time. In this stage the sleeper has minimum inertial to wake-up hence it is called light sleep. Light sleep also accounts for growth, tissue repair, and memory consolidation but effects are not as intensified as Deep Sleep.
Graph with light sleep highlighted:
Benefits of Light Sleep
Light sleep is very important, “It’s when your body processes memories and emotions and your metabolism regulates itself. So there’s a lot of body maintenance occurring during lighter stages of sleep.”
Risk Factors due to lack of light sleep
Adults who sleep less than 7 hours each night are more likely to say they have had health problems, including heart attack, asthma, and depression. Some of these health problems raise the risk of heart disease, heart attack, and stroke. These health problems include:
- High blood pressure.
- Type 2 diabetes
Tips to Improve light sleep
- Stick to a regular sleep schedule. Go to bed at the same time each night and get up at the same time each morning, including on the weekends.
- Get enough natural light, especially earlier in the day. Try going for a morning or lunchtime walk.
- Get enough physical activity during the day. Try not to exercise within a few hours of bedtime.
- Avoid artificial light, especially within a few hours of bedtime. Use a blue light filter on your computer or smartphone.
- Don’t eat or drink within a few hours of bedtime, especially alcohol and foods high in fat or sugar.
- Keep your bedroom cool, dark, and quiet.
Deep sleep also known as the slow-wave sleep is responsible for muscle relaxation and a slower breathing rate which leads to tissue growth and repair. It is also important for hormonal balance restoration. Deep sleep is usually prominent in the first half of the sleep.
Benefits of Deep Sleep
Glucose metabolism in the brain increases during deep sleep, supporting short-term and long-term memory, and overall learning. Deep sleep is also when the pituitary gland secretes important hormones, like human growth hormone, leading to growth and development of the body.
Other benefits of deep sleep include:
- energy restoration
- cell regeneration
- increasing blood supply to muscles
- promoting growth and repair of tissues and bones
- strengthening the immune system
Risk Factors due to lack of deep sleep
There is clear evidence that a lack of sleep has profound effects on health. When deep sleep is compromised, the quality of sleep plummets. As noted above, there can be important impacts on the body and, importantly, the brain. Consider these consequences:
- Pain: Chronic pain is exacerbated by reduced deep sleep. This may manifest in various ways, including as a clinical diagnosis of fibromyalgia. As sleep depth improves, pain may abate.
- Impaired growth: Children who have untreated sleep disorders like sleep apnea experience reduced deep sleep, which impairs the release of growth hormone. Fortunately, once effectively treated, these children may experience a growth rebound.
- Dementia: The accumulation of beta-amyloid plaques within brain tissue characterizes the development of memory impairment and Alzheimer’s disease. A lack of deep sleep, and the disturbance of the process of cleansing the brain of these proteins, may accelerate this degeneration.
It is likely that a lack of deep sleep also contributes to immune system dysfunction and the risk of routine infections, such as the common cold or influenza, as well as the risk for chronic diseases like cardiovascular disease and even cancer.
Tips to improve Deep Sleep
- Power Down Your Devices
- Listen to Pink Noise like the rustling of leaves, waves touching the shore, etc.
- Stick With Your Natural Sleep-Wake Cycle - Be Smart With Your Food Intake - Follow A Bedtime Ritual - Use A White Noise Machine
REM (Rapid Eye Movement Sleep) is a unique phase of sleep distinguished by the rapid movement of the eyeballs, accompanied by relaxed muscles throughout the body, and the propensity of the sleeper to dream vividly. REM sleep helps in memory consolidation.
On average you'll go through 3-5 REM cycles per night, with each episode getting longer as the night progresses. The final one may last roughly an hour. For healthy adults, spending 20-25% of your time asleep in the REM stage is a good goal.
Benefits of REM Sleep
REM sleep is believed to benefit learning, memory, and mood. It is also thought to contribute to brain development in infants. A lack of REM sleep may have adverse implications for physical and emotional health, and central nervous system (CNS) development. REM sleep may be especially important for brain development in infants. Some research indicates that this sleep stage is responsible for the neural stimulation necessary to develop mature neural connections.
Risk Factors due to lack of REM sleep
- Reduced coping skills – research indicates that animals who are deprived of REM sleep show abnormalities in coping mechanisms and defensive responses in threatening situations.
- Migraines – not getting enough REM sleep has been linked to migraines.
- Obesity – a University of Pittsburgh study found that short sleep times and reduced REM sleep was associated with excess weight in children and adolescents
Tips to Improve REM sleep
- Establish a bedtime routine - Reduce night time waking - Get enough sleep - Address medical conditions - Avoid alcohol before bedtime
Sleep requirements vary slightly from person to person, most healthy adults need between 7 to 9 hours of sleep per night to function at their best. Children and teens need even more. And despite the notion that our sleep needs decrease with age, most older people still need at least 7 hours of sleep.
Tips to improve sleep efficiency
- Create a Sleep Sanctuary
- Enhance the Association Between the Bed and Sleep
- Observe Stimulus Control and Get Up If Awake
Sleep latency also called sleep onset latency is the amount of time it takes you to go from being fully awake to sleeping. Sleep latency varies from person to person. Your sleep latency and how quickly you reach rapid eye movement (REM) sleep can be indicators of the amount and quality of sleep you’re getting.
Graph highlighting sleep latency (time to sleep)
Normal adults mean sleep latency is between 10 and 20 min. Pathologic sleepiness is defined as a mean sleep latency <5 min and this has been associated with impaired performance. According to the AASM, a sleep latency of <8 min is diagnostic of sleepiness.
Causes and Risk Factors
The cumulative long-term effects of sleep loss and sleep disorders have been associated with a wide range of deleterious health consequences including an increased risk of hypertension, diabetes, obesity, depression, heart attack, and stroke.
- Age-related sleep changes As you get older, changes in your circadian rhythm cause you to need fewer hours of sleep at night. This might disrupt your sleep patterns and cause you to wake in the early morning hours before you’ve intended to start your day. Women experiencing hormonal shifts due to menopause might have disrupted sleep. And men experiencing urinary problems because of age-related changes in the prostate might also find it harder to sleep through the night.
- Anxiety Anxiety in all its forms can disrupt your sleep. While sleep-onset insomnia, the kind of insomnia that prevents you from falling asleep when you want to is most often associated with anxiety, feeling anxious about a situation or event can also cause you to sleep fewer hours at a time. Anxiety disorders are widely associated with insomnia of all kinds.
- Insomnia Insomnia is a sleeping disorder characterized by the inability to fall asleep, stay asleep, or both. People who deal with insomnia can have either short-term (acute) or long-term (chronic) symptoms. Acute insomnia is usually situational and can last anywhere from a few days to several weeks. If you’re experiencing insomnia more than three times per week, for longer than three months, you could be diagnosed with chronic insomnia.
Tips to reduce Sleep Latency
- Learn Your Rhythm: Aligning your sleep schedule with your body’s internal clock can help you sleep well and wake up feeling more refreshed.
- Power Down Electronics: For better sleep, turn off all electronics before bedtime.
- Remove the Evidence: Remove all clocks from your line of sight once you are in bed. Not being able to count the minutes as you lie awake can take some pressure off the situation, reducing your stress and helping sleep come more naturally.
- Darken the Room: Use light-blocking shades for your windows, close your bedroom door and turn off or cover the light that’s emitted from electronic devices. You can also wear an eye mask to complete your total blackout.
- Meditate: Practice breathing exercises that quiet the mind, then work on applying these skills to your bedtime routine.
Snoring is a harsh sound while breathing, which is produced by nose or mouth while sleeping. The causes for snoring include congestion of nose, the anatomy of mouth and sinuses, alcohol consumptions, etc.
Graph with snoring highlighted
The number of apneas and hypopneas per hour of sleep was termed the apnea/hypopnea index (AHI) and the number of snores per hour of sleep was termed the snoring index (SI). For each epoch, we also computed snoring frequency, defined as the number of snores per epoch.
We used the mean maximum decibel level to classify snoring as mild (40-50 dB), moderate (50-60 dB), or severe (> 60 dB).
Snoring can be caused by a number of factors, such as the anatomy of your mouth and sinuses, alcohol consumption, allergies, a cold, and your weight.
- Your mouth anatomy: Having a low, thick soft palate can narrow your airway. People who are overweight may have extra tissues in the back of their throats that may narrow their airways. Likewise, if the triangular piece of tissue hanging from the soft palate (uvula) is elongated, airflow can be obstructed and vibration increased.
- Alcohol consumption: Snoring can also be brought on by consuming too much alcohol before bedtime. Alcohol relaxes the throat muscles and decreases your natural defenses against airway obstruction.
- Nasal problems: Chronic nasal congestion or a crooked partition between your nostrils (deviated nasal septum) may contribute to your snoring.
- Sleep deprivation: Not getting enough sleep can lead to further throat relaxation.
- Sleep position: Snoring is typically the most frequent and loudest when sleeping on the back as gravity's effect on the throat narrows the airway. Risk Factors Some people are more likely to snore than others. Snoring occurs somewhat more often in men than in women. Snoring is not uncommon in women and becomes more common during pregnancy. Snoring becomes more prevalent with age, for both men and women. Other risk factors for snoring include:
- Being overweight
- Drinking alcohol
- Nasal conditions, including deviated septum or frequent congestion
- Family history of snoring or other sleep-disrupted breathing
In some instances, the shape and construction of a person’s airway, head, or neck may predispose them to snore, even when other risk factors are not present.
Tips to reduce snoring
- Avoiding alcohol close to bedtime
- Treating nasal congestion
- Avoiding sleep deprivation
- Avoiding sleeping on your back
- Losing weight
Slight move during sleep. These movements include small twitches to posture changes. Generally, these movements happen in pockets during our sleep, but sometimes when we are sick or exceptionally tired these movements increase, not letting us sleep properly and might end up waking us up.
Graph with Restlessness highlighted:
Causes and Risk Factors
Tossing and turning in bed is normal every now and then. It could be due to stress or your diet: Drinking too much caffeine or alcohol and eating salty snacks and refined carbs (like bread or white rice) before bedtime can lead to sleep-interrupting fidgetiness. But if restless sleep becomes a chronic problem, it’s best not to ignore the issue since it could be a sign of one the following more serious conditions:
- Rapid Eye Movement Sleep Behavior Disorder (RBD) Most people remain still during their dreams, but those with RBD act out their dreams, moving their limbs about, walking, and even hitting and punching. Because RBD can lead to injuries and may be associated with an increased risk of developing Parkinson’s disease, it’s important to talk with a doctor or sleep specialist if you think you may have RBD. A doctor might prescribe medication such as melatonin or clonazepam to treat the disorder.
- Restless Leg Syndrome (RLS) Also called Willis-elbow disease, RLS causes an urge to keep moving the legs throughout the night due to uncomfortable sensations. Getting up and walking around or stretching the legs in bed can ease the discomfort but, of course, this restlessness also interferes with sleep. Luckily, treatment is available, including leg massage, heat pads or ice packs, and using a foot wrap that puts pressure on certain muscles in the foot. If that doesn’t work, your doctor may suggest taking iron supplements or prescription medication such as anti-seizure drugs, dopaminergic agents, and benzodiazepines, which have shown some success in reducing RLS symptoms.
- Obstructive Sleep Apnea (OSA) Loud snoring and frequent gasp-like interruptions in breathing throughout the night can be a sign of obstructive sleep apnea, a disorder that, if left untreated, can increase the odds of restless sleep, heart trouble, diabetes, and more. Additional symptoms include drowsiness during the day and waking up with a headache, sore throat, or dry mouth. See a physician if you think you may be affected by OSA. A doctor may recommend lifestyle changes, such as losing weight or exercising more frequently or prescribe a sleep mask that keeps the airways open throughout the night.
Tips to reduce restlessness
If sleep hygiene issues are causing you to be restless at night, you should avoid daytime naps and the use of electronic devices before bed, establish regular sleep/wake times and get regular exercise and exposure to natural light.