Effects of Sleep

Not Sleeping Enough can be Deadly: 

In this fast moving world, as the pace of life gets faster and faster, people try to squeeze more time to make up the day. As things get more hectic, sleep tends to get short shrift. It’s seen as wasted time, lost forever. “For healthy people, there’s a big temptation to voluntarily restrict sleep, to stay up an hour or two or get up an hour or two earlier,” said Dr. Greg Belenky, director of the Sleep and Performance Research Center at Washington State University “But you’re really reducing your productivity and exposing yourself to risk,” Belenky added.

You would have hardly ever thought about the wonderful sleep process that we indulge in at end of the day everyday. We all get on to the bed and in few minutes we are into reversible hibernation mode, away from the all the thought process and worries of the world until we wakeup the next morning with either the buzz of an alarm ring or by virtue of the biological clock that wakes you up from the sleep process. Experts recommend seven to eight hours of sleep each night; the amount needed for an individual can vary. Before Thomas Edison invented the light bulb in 1880, people slept an average of 10 hours a night. Let’s know what sleep is, how is it defined and how it is important for our lives.

Sleep is defined as a state of unconsciousness from which a person can be aroused. In scientific terms, sleep is a naturally recurring state of relatively suspended sensory and motor activity, characterized by total or partial unconsciousness and the inactivity of nearly all voluntary muscles. In this state, the brain is relatively more responsive to internal stimuli than external stimuli. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and it is more easily reversible than hibernation or coma. Sleep is a heightened anabolic state, accentuating the growth and rejuvenation of the immune, nervous, skeletal and muscular systems. It is observed in all mammals, all birds, and many reptiles, amphibians, and fish.

Importance of Sleep:

In humans, other mammals, and a substantial majority of other animals that have been studied (such as some species of fish, birds, ants, and fruit flies), regular sleep is essential for the normal, healthy functioning of the human body. It is a complicated physiological phenomenon that scientists do not fully understand till date.

Earlier, sleep was thought to be a passive state. However, sleep is now known to be a dynamic process, and our brains are active during sleep. Sleep affects our physical and mental health, and is essential for the normal functioning of all the systems of our body, including the immune system. The effect of sleep on the immune system affects one’s ability to fight disease and endure sickness.

Animal studies have shown that sleep is necessary for survival. The normal life span of rats is 2-3 years. However, rats deprived of sleep live for only about 3 weeks. They also develop abnormally low body temperatures and sores on their tails and paws. The sores probably develop because of impairment of the rats’ immune systems.

In humans, it has been demonstrated that the metabolic activity of the brain decreases significantly after 24 hours of sustained wakefulness. Sleep deprivation results in a decrease in body temperature, a decrease in immune system function as measured by white blood cell count, and a decrease in the release of growth hormone. Sleep deprivation can also cause increased heart rate variability.

A sound sleep is required for the nervous system to work properly. Sleep deprivation makes a person drowsy and unable to concentrate the next day. It also leads to impairment of memory and physical performance and reduced ability to carry out mathematical calculations. If sleep deprivation continues, hallucinations and mood swings may develop.

Release of growth hormone in children and young adults takes place during deep sleep. Most cells of the body show increased production and reduced breakdown of proteins during deep sleep. Sleep helps humans maintain optimal emotional and social functioning while we are awake by giving rest during sleep to the parts of the brain that control emotions and social interactions.

Stages of Sleep:

There are 2 distinct states that alternate in cycles and reflect differing levels of neuronal activity. This state is characterized by different types of brain wave activity (electrical activity that is recorded with the help of electrodes placed on the skull). Sleep consists of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM is further subdivided into the following 4 stages:

  • Stage I (light sleep)
  • Stage II
  • Stage III & IV (deep sleep)

The stages of NREM sleep and REM sleep, cycle over and over again during a night’s sleep. Stages I, II, III, and IV are followed by REM sleep. A complete sleep cycle, from the beginning of stage-I to the end of REM sleep, usually takes about one and a half hours.

For the purpose of analysis, a night’s sleep is divided into 3 equal time periods: sleep in the first third of the night, which comprises the highest percentage of NREM; sleep in the middle third of the night; and sleep in the last third of the night, the majority of which is REM. Awakening after a full night’s sleep is usually from REM sleep.

NREM Sleep (Non-Rapid Eye Movement :

Stage-I is a stage of light sleep and is considered a transition between wakefulness and sleep. During this stage, the muscles begin to relax. It occurs upon falling asleep and during brief arousal periods within sleep, and usually accounts for 5-10% of total sleep time. An individual can be easily awakened during this stage.

Stage-II occurs throughout the sleep period and represents 40-50% of the total sleep time. During stage II, brain waves slow down with occasional bursts of rapid waves. Eye movement stops during this stage.

Stage-III, extremely slow brain waves called delta waves begin to appear. They are interspersed with smaller, faster waves.

Stage IV, delta waves are the primary waves recorded from the brain. These 2 stages are distinguished from each other only by the percentage of delta activity. Together they represent up to 20% of total sleep time. Stages III and IV are called deep sleep, during which all eye and muscle movement ceases. It is difficult to wake up someone during these 2 stages. If someone is awakened during deep sleep, he does not adjust immediately and often feels groggy and disoriented for several minutes after waking up. Some children experience bedwetting, night terrors, or sleepwalking during deep sleep.

REM sleep (Rapid Eye Movement) :

REM sleep represents 20-25% of the total sleep time. REM sleep follows NREM sleep and occurs 4-5 times during a normal 8- to 9-hour sleep period. The first REM period of the night may be less than 10 minutes in duration, while the last may exceed 60 minutes. In a normal night’s sleep, bouts of REM occur every 90 minutes.

When the person is extremely sleepy, the duration of each bout of REM sleep is very short or it may even be absent. REM sleep is usually associated with dreaming. During REM sleep, the eyeballs move rapidly, the heart rate and breathing become rapid and irregular, and the blood pressure rises. The muscles of the body are virtually paralyzed. The brain is highly active during REM sleep, and the overall brain metabolism may be increased by as much as 20%. The electrical activity recorded in the brain during REM sleep is similar to that which is recorded during wakefulness.

Dangers of not Sleeping Enough:

Lack of sleep affects a person in one of two ways, says Dr. Greg Belenky, director of the Sleep and Performance Research Center at Washington State University.
First sleeplessness influences the day-to-day performance of tasks. “The performance effects are seen immediately,” he said. “You short-change yourself of sleep, and you see the effects immediately. You can make a bad decision. You can miss something. Have a moment’s inattention, and you’re off the road.

The long-term effects of sleep deprivation involve a person’s health. It is ascertained that problems like weight gain, diabetes, high blood pressure, heart problems, depression and substance abuse are due to lack of sleep. “Hormones that process appetites begin to get disorganized,” said Drake, who’s also an assistant professor of psychiatry and behavioral neuroscience at the Wayne State University School of Medicine. There’s a decrease in the amount of leptin, an appetite-suppressing hormone, when a person gets too little sleep. At the same time, ghrelin — a hormone that stimulates appetite — increases with a lack of sleep.

Too little sleep also interferes with the body’s ability to regulate glucose and can cause inflammation leading to heart problems and a rise in blood pressure. “There’s a stress response to being in a sleep loss,” Belenky said. The types of people not getting enough sleep also break down into two groups. First, there are those who make the conscious choice to go without enough sleep.

In a study, funded by the British and U.S. governments, around 10,000 government workers were tracked over a period of 17 years. People who slept five to seven hours or less had a 1.7-fold-increase risk in mortality and more than double cardiovascular risk of death. Prof: Francesco Cappaccio, of cardiovascular medicine at the University of Warwick’s medical school said, “A third of the population of the U.K. and over 40 percent in the U.S. regularly sleep less than five hours a night, so it is not a trivial problem.”

Above all, there are people who are suffering from sleep disorders. These disorders include:

  • Insomnia, is inability to go to sleep or stay asleep
  • Sleep apnea or breathing interruptions during sleep that cause people to wake up repeatedly.
  • Restless legs syndrome, a tingling or prickly sensation in the legs that causes a person to need to move them, interrupting sleep.
  • Someone suffering from any of these problems should visit their doctor or see a sleep specialist, Belenky said.
  • Sleep apnea, the most prevalent sleep disorder, can have particularly serious long-term effects if left untreated. “You’re waking up out of sleep to breathe. You can’t sleep and breathe at the same time,” Drake said. “It’s a risk factor for developing major cardiovascular health effects.”
  • “Sleeping pills are a temporary solution,” Belenky said. “If you’re upset about something or have situational insomnia, or you’re trying to sleep at the wrong time of day because you’ve traveled across time zones, they are effective.”

Tips for a Good Night Sleep: 

According to the U.S. National Institutes of Health offers these tips for getting a good night’s sleep:

  1. Stick to a regular sleep schedule.
  2. Avoid exercising closer than five or six hours before bedtime.
  3. Avoid caffeine, nicotine and alcohol before bed.
  4. Avoid large meals and beverages late at night.
  5. Don’t take naps after 3 p.m.
  6. Relax before bed, taking time to unwind with a hot bath, a good book or soothing music.
  7. If you’re still awake after more than 20 minutes in bed, get up and do something relaxing until you
  8. Feel sleepy. Anxiety over not being able to sleep can make it harder to fall asleep.

Hope after reading through this article, you would have understood the importance of sleep in leading a successful life, for people who have problem sleeping can consult a doctor and find a permanent cure, and for professionals and students who squeeze time from their sleep hours, it’s high time to reschedule their timings.

For more updates visit HarNeedi.com OR Follow us at Facebook, Twitter and Google+.