What is sleep?
Sleep is a state of altered consciousness of the mind and body which typically lasts for several hours every night. It involves the inactivity of the nervous system, relaxation of all the muscle of the body and is considered important for optimal health.
The normal sleep pattern involves the alternating REM (rapid eye movement) and NREM (non-rapid eye movement) sleep that occurs in a 90-minute interval cycle in a typical night’s sleep.
There are four phases:
Stage 1: Light sleep – between being awake and sleeping
Stage 2: Initiating sleep, drop in the body temperature, regular heart rate and breathing.
Stage 3 and 4: The deepest form of sleep when the breathing slows down and the blood supply to all the organs increases, the repair process begin, muscles are relaxed, the blood pressure goes down, various hormones like growth hormone are released.
What is the importance of REM and NREM?
REM makes up about 25% of the night’s sleep: It first begins about 90 minutes after falling asleep. Lasts for some time and recurs about every 90 minutes. In the REM stage, the brain is more active, heart rate is raised and intense dreams can occur. At this stage, brain development occurs as the area of learning in the brain is stimulated.
Like deep NREM sleep, REM sleep also helps protein binding for growth.
During the NREM sleep, the body restores its functions of the brain, repairs and regrows tissues, promotes growth, and improves the immune system.
Benefits of sleep
Normal Brain function and development: Sleep is essential for maintaining the normal levels of cognitive skills. ( This include speech, memory, innovative and focused thinking.)
Emotional well-being: Sleep can give you a feeling a sense of freshness, motivation and relaxation.
- Sleep will help maintain hormonal balance in the body. For example, the hormones that regulate hunger and insulin regulation for blood sugar levels.
- It is involved in the healing process of your heart and blood vessels.
- It can support growth and development in children and teens by releasing hormones that builds muscle mass and helps the body repair.
- It plays a role in puberty and fertility.
- It can improve immunity and help fight infections better.
Good physical performance levels:
- Sleep can improve concentration, focus, awareness and general activeness of your body.
- It improves your ability to perform skillful activities.
How much sleep is recommended?
|Age||Recommended Amount of Sleep|
|Newborn babies||about 17 to 18 hours per day|
|Preschool children||about 11 to 12 hours per day|
|School children||Minimum 10 hours per day|
|Teenagers||about 9 to 10 hours a day|
|Adults (including the elders)||about 7 to 8 hours a day|
Sleep deficiency can increase the risk for some chronic health problems.
- Heart disease: Lack of sleep will keep the heart rate elevated leading to increased calcification (calcium deposits) in the blood vessels of the heart. There is also an increase in CRP (C-reactive protein), which is released with stress and inflammation that can lead to heart problems.
- Obesity: Lack of sleep can interfere with appetite regulation due to imbalances in the hormones that regulate hunger. This can lead to eating at night when your body’s metabolism is low causing excessive fat storage leading to obesity.
- Diabetes: Due to the increase in food intake and lack of rest, hormonal imbalances can affect the insulin response in the body. The metabolism of glucose is affected due to insulin resistant that can lead to type 2 Diabetes.
- High blood pressure: With insufficient rest, the heart rate remains elevated. This raises the blood pressure which may cause hypertension.
- Stroke or transient ischemic attack (mini-stroke): It is related to elevated heart rate and hypertension that can lead to a reduction of blood supply to the brain leading to a stroke or mini-stroke.
- Depression and attention-deficit hyperactivity disorder (ADHD): Due to lack of rest and interference in the brain function, lack of sleep can cause problems with thinking, mood swings, depression and hormonal imbalances that may lead to ADHD and depression.
Sleep Disorders – There can be about 81 disorders.
- Insomnias (Sleeplessness): There can be difficulty at the beginning of sleep, maintaining sleep, abrupt waking from sleep, waking too early or poor quality sleep. This sleep difficulty can occur despite all attempts of trying hard to sleep. This can be related to mental disorder, restless leg syndrome, sleep apnea or due to drug side-effects.
- Sleep-related breathing disorders: Cheyne-Stokes breathing pattern is characterized by a gradual increase in the breathing followed by a gradual decrease and holding of breath for 5 to 50 seconds. This type of respiratory problem is also typically seen with other medical problems of the heart and kidney.
- Sleep apnea: Irregular breathing pattern with disruption or episodes of breathlessness. It can be due to lack of sleep causing arterial oxygen desaturation (reduction in oxygen in the blood).
- Hypersomnias (Narcolepsy): This involves daytime sleepiness and may be related to dysfunction in the brain due to increased lack of sleep at night or misaligned circadian rhythms (body clock).
- Circadian rhythm sleep disorder: The “body clock” or the circadian rhythm is the 24-hour cycle that tells your body when to sleep and helps to regulate many other physiological processes. Disturbances can occur between the person’s sleep pattern and the pattern that is desired. For example, one cannot sleep when sleep is desired.
- Parasomnias: The parasomnias consist of abnormal sleep-related movements, behaviors, emotions, perceptions or dreaming. It occurs while falling asleep, sleeping, between sleep stages, or during arousal from sleep. They are disorders that cause sudden waking up or a state of disturbed sleep.
- Sleep-related movement disorders: Restless legs syndrome, sleep-related rhythmic movement disorder, large movements of the body or legs while sleeping can affect normal sleep pattern.
Snoring is a sound produced by breathing. Snoring can also lead to impaired health as it can disturb the sleep of the individual and their sleeping partner.
Sleep talking and sleep walking can be associated with REM sleep behavior disorder or sleep-related eating disorder. Usually, the person can get a sensation of falling, a sensory flash of walking to a place or a sleep-onset dream that can cause talking or walking.
Who can be at risk of sleep disorders?
- Working on odd timings/shifts: Job timings that are against the internal body clock and working long hours.
- Lifestyle problems: People who take medications to stay awake to complete tasks and studies. Other problems like alcohol or substance abuse.
- Known or unknown medical condition: People who take medications that have side-effects that interfere with sleep. People with underlying unknown problems like stress and anxiety.
How is sleep problems diagnosed?
- Blood Tests can be done to help find other underlying medical problems that can cause sleep problems.
- Sleep studies (polysomnography): The electric activity in the brain (Electroencephalogram studies), behavior and other changes are observed while the person is asleep to study the problems associated.
How to get a good amount of sleep?
- Sleep schedule should be kept the same every night. Avoid differences that may disturb your body clock.
- Avoid strenuous exercise or doing work before bed as that will keep your brain active and delay sleep.
- Avoid cigarettes (nicotine) and caffeine. Nicotine and caffeine are brain stimulants so both substances can interfere with sleep.
- Getting enough fresh air and sun during the day can also help a good night’s sleep.
- Learning relaxation techniques like breathing exercises can help.
- Taking a warm shower before sleep can also relax the body. Keeping the bedroom cool and dark will also help prevent any disturbances.
If you have any type of sleep issues due to a shift-work schedule, it’s best to speak to your employer or consider visiting the experts to better understand your issues and eliminate the worry of any underlying medical condition.