Sleep Stages
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
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
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:
- High blood pressure.
- Type 2 diabetes
- Obesity
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
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 Let’s face it. We are glued to our smartphones and tablets throughout the day, from the moment that we wake up, up to the point when we get to bed. Unfortunately, the bright light that is coming from these devices actually stimulates the brain, which in turn can affect our sleep. If you want to be able to get more shut-eye at night, power down your devices at least an hour before bedtime so that you don’t expose yourself to blue light.
- Get The Right Temperature For Your Bedroom People have different preferences when it comes to the temperature in their bedroom. Some prefer it hot, while others like it cold. However, both science and physiology agree that the best temperature for us at night is 60-67 degrees. So, if you want to enjoy deeper sleep, make sure that the temperature in your room is set accordingly.
- Exercise According to the National Institutes of Health, we need to exercise at least half an hour per day, five days a week. This can help improve sleep and sleep quality as well. However, you shouldn’t work out close to bedtime as it can also cause sleep deprivation which may lead to insomnia. You don’t have to do extreme exercises, because you can start with something simple as walking the dog, yoga, and even light jogging works too.
- Pink Noise Another tip on how to get more deep sleep is to try pink noise. Pink noise is similar to the rustling of leaves and the sound of the waves touching the shore. These sounds have been found to contribute to the amount of time we spend in deep sleep.
- Stick With Your Natural Sleep-Wake Cycle It is important that you follow your sleep-wake cycle, or circadian rhythm, as much as possible to sleep better at night. When you follow a daily sleep and wake schedule every day, you’ll find yourself feeling more refreshed and energized compared to sleeping at different times or sleeping in over the weekend. This also includes taking a nap in the afternoon. If your sleep is disrupted at night because of your taking a nap in the afternoon, you might want to skip it altogether. Make sure that you stick to a consistent sleep schedule throughout the week.
- Be Smart With Your Food IntakeAnother tip on how to sleep better at night is to focus on what you’ve been eating throughout the day. For example, drinking excessive amounts of caffeine can disrupt your sleep, as it is a stimulant. You should avoid overeating during dinner or consuming foods that are heavy and rich because they will need time to be digested. This can also affect your sleep. Consuming spicy foods can trigger heartburn and stomach issues as well, which can keep you from getting a good night’s sleep.
- Follow A Bedtime RitualFor those who are having a hard time sleeping, following a relaxing bedtime routine can help prepare you for bed at night. This routine should be centered on making you feel calm and relaxed. Avoid stimulating, stressful, or exciting situations that will keep you wide awake at night. Think meditation, listening to soft music, or doing some light stretches to relax those tense muscles.
- Use A White Noise MachineThere are many sources of sound in your bedroom at night, from the sound of car horns blaring, the loud music from your neighbor or even the sound of your partner snoring. All these distractions can prevent you from entering deep sleep. That being said, setting up a white noise machine that can drown out the rest of the outside noises may help you fall asleep.
REM Sleep
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.
- 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 Following the same bedtime routine every night prepares the body and mind for sleep. A regular bedtime routine may help to maximize the amount of time asleep, potentially increasing the number of REM sleep phases experienced.
- Reduce night time waking Loud sounds, warm temperatures, and bright lights can interrupt sleep. For optimal sleeping conditions, switch off cell phones and other sources of noise, and remove light sources from the bedroom. Keep temperatures between 60 and 67 degrees Fahrenheit.
- Reduce night time waking Loud sounds, warm temperatures, and bright lights can interrupt sleep. For optimal sleeping conditions, switch off cell phones and other sources of noise, and remove light sources from the bedroom. Keep temperatures between 60 and 67 degrees Fahrenheit.
- Get enough sleep A healthy adult requires 7-9 hours of sleep a night. Sleeping less than this reduces the number of REM sleep phases experienced.-
- Address medical conditions Certain medical conditions, such as sleep apnea, can affect sleep quality and impact REM sleep.
- Avoid alcohol before bedtime As moderate to high levels of alcohol intake before bed can reduce the number of REM sleep phases experienced, and any amount delays entering the first REM phase, it is advisable to avoid alcohol consumption in the hours before bed.
Sleep Efficiency
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 The first thing to do to improve sleep efficiency is to reserve the bed and bedroom as a space for sleep. This may involve eliminating all potential distractions when sleeping. There should be no television on and no music playing. If you are accustomed to having the television or music on, you should work to break those habits and go to sleep in a quiet, dark, and peaceful atmosphere.
- Enhance the Association Between the Bed and Sleep The bed should not be used for activities other than sleep or sex. This should also help to improve sleep efficiency. Participating in activities other than sleeping in bed, such as reading a book or watching TV, trains you to associate the bed with awake-time activities. Lying awake and reading for 2 hours adds to the total time in bed, greatly reducing the calculated sleep efficiency. The bed should be associated with sleeping or falling asleep only, and thus all other activities should be eliminated from the bed.
- Observe Stimulus Control and Get Up If Awake According to the rules of stimulus control, if you are awake for longer than 15 to 20 minutes, it is recommended that you get up, leave the bedroom, and do something relaxing. Once you begin to feel sleepy again, return to the bedroom to sleep. This helps to retrain you to sleep better in bed.
Sleep Latency
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.
Ideal Range
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</br> 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. Many adults in the middle of life report difficulties sleeping not only due to age-related and hormonal shifts, but also due to circumstantial issues. Anxiety, acting as caregiver to one or both aging parents, medications, loss of a partner due to death or divorce, having an “empty nest,” work-related stress, and more can cause people in midlife to have trouble staying asleep.
- 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. But you don’t have to have an anxiety disorder to experience problems going to sleep or staying asleep. The simple situation of waking up a few hours before your alarm is supposed to ring can create so much anxiety that you can’t get back to sleep.
Watching the clock and worrying about how little sleep you’ve gotten, whether you’ll get the rest of the sleep you want, and fearing you’ll miss your alarm if you do go back to sleep can all keep you wide awake in the early morning hours.
Insomnia</br>
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 A circadian rhythm is your body’s system for sleeping and waking during a 24-hour day. By paying attention to this rhythm, you can determine what times during the day you feel alert and when you feel tired. Use this information to establish your daily routine, including the hour you wake up and go to bed every night. Aligning your sleep schedule with your body’s internal clock can help you sleep well and wake up feeling more refreshed.
Remove the Evidence The perception of lost sleep can be annoying. One way to avoid this mental angst is to 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 Lights from street lamps, hallway nightlights, or even the glow from your TV’s cable box can be needless distractions when you’re trying to get some sleep. To be sure these pesky sources of illumination don’t affect your sleep latency, 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 Meditating is a great technique for calming your thoughts and removing your worries so that you can get ready to sleep. Signing up for group yoga or guided meditation classes in your area can teach you useful relaxation skills. Practice breathing exercises that quiet the mind, then work on applying these skills to your bedtime routine.
WASO - Wake up After Sleep Onset
An important reported parameter is wake after sleep onset, also known as 'WASO'. This refers to periods of wakefulness occurring after defined sleep onset. This parameter measures wakefulness, excluding the wakefulness occurring before sleep onset. WASO time is a better reflection of sleep fragmentation.
Snoring
Snoring is a harsh sound while breathing, which is produced by nose or mouth while sleeping. The causes for snoring include congestion of nose, anatomy of mouth and sinuses, alcohol consumptions etc.
Causes and Risk Factors
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 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 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 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
- Smoking
- 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 snoring, 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
Restlessness
We tend to move during our 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
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 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 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 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
- Smoking
- 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 snoring, 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
Restlessness
We tend to move during our 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-ekbom 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 prescribe 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.