Sleep - What You Should Know
The Beauty of Sleep
Sleep is a basic, essential human need. Living in our 24/7 world, our sleep habits can become disrupted, and it becomes easy for us to take sleep for granted with so many things to do. We can build a sleep debt as easily as we can build a credit card debt.
Eight hours a night was once seen as the ideal sleep, but now we know the complex process is regulated by the brain and follows the ticking of our biological clock. It is estimated that 40 million Americans suffer from sleep disorders, with an estimated 18 billion dollars lost in productivity.
Sleep is the best meditation.
Dalai Lama
The Importance of Sleep
Although we all need sleep, our sleeping patterns change throughout our lives. Newborns sleep frequently for shorter periods - about 18 hours a day. Teenagers need about 9 hours. While some adults claim to need only 3 hours a day, others 10 hours, the norm is 7 to 8 hours.
During puberty, our biological clock shifts forward, which explains why teenagers want to sleep later and wake up later. Caffeine keeps us awake by blocking the chemical compound that signals our need for sleep.
Animal studies show that a rat deprived of all sleep can only survive 3 weeks. What does that mean for us? When our sleep cycle is interrupted, we acquire what is called a sleep debt. Sleep deprivation can impair our immune system, affect brain function, and result in physical ailments and inefficiency.
What Happens When We Sleep
Sleep has a restorative effect on the brain, which recovers from the efforts of the day. Some experts believe learning continues while we sleep - that what we have learned is put into place in our mind at night. On the other hand, lack of proper rest can impair learning. Individuals taught new skills then deprived of REM sleep could not recall them later
Sleep produces the hormone leptin, which regulates our appetite and lets us know when we are full. When we are awake for too long, we produce less, resulting in a craving for carbohydrates that can lead to weight gain and obesity. Sleep also makes it easier for our bodies to eliminate free radicals, related to the aging of cells and cancer. Experts also believe neurons active during the day need to shut down and repair themselves in order for our nervous systems to function properly.
The Different Phases of Sleep
There are two basic types of sleep - REM and non-REM sleep. Non-REM sleep stages vary from a light sleep to a deep sleep. During deep sleep, our blood pressure and heart rate lowers, resting our circulatory system. It is believed this wards off circulatory disease. Growth hormones peak during non-REM sleep, with teenagers producing more than 50 times the amount at night than during the day.
REM sleep is the phase of sleep where the eye moves rapidly every 60 to 90 minutes through the night. This is when the brain is most active. Sleep experts believe that the brain is performing a type of self-repair during this phase. REM generally occurs 70 to 90 minutes after we fall asleep. As the night progresses, REM sleep periods becomes longer. During this phase, our body experiences maximum muscle relaxation, allowing us to wake up physically refreshed.
Having Trouble Sleeping? - Sometimes we need a little advice.
The best cure for insomnia is to get a lot of sleep.
W.C. Fields
What Is Sleep Debt?
It wrecks cars and ruins relationships. It affects health and shortens life spans. It has been linked to the nuclear disaster at Chernobyl, the explosion of the Challenger space shuttle, and the Exxon Valdez oil spill in Alaska. Getting too little sleep creates a sleep debt that our bodies will eventually demand repaid.
We can't adapt to a sleep-deprived schedule. Lack of proper rest can impair our judgement, reaction times, and ability to create, plan, and carry out activities. If you feel drowsy during the day, you have not had enough sleep. Sleep debt is linked to diabetes, heart disease, cardiovascular diseases, and chronic memory loss.
When our REM sleep is disrupted, we build a sleep debt. Our bodies will not follow a normal cycle of sleep the next time we go to bed. We slip into REM sleep quickly, going through extended periods until we are caught up.
The National Highway Traffic Safety Administration estimates 100,000 motor vehicle accidents and 1500 deaths a year are related to sleep deprivation. Drowsiness is the brain's last signal to falling asleep. If you can't keep your eyes focused while you are driving, if you can't stop yawning, or if you can't remember the last few miles you have driven, you are probably too drowsy to drive. You can be forced into a microsleep, lasting from 10 seconds to 1 minute. At 30 miles an hour, you can travel the length of a football field.
Causes of Insomnia
Once viewed as disorder, it is now considered to be a symptom of other problems.
- Apnea - the closing of upper air passages during sleep
- Restless legs syndrome
- Alzheimer's disease
- Periodic limb movement disorder - movements accompanied by periods of wakefulness
- Asthma
- Parkinson's disease
- Depression and anxiety
- Obsessive compulsive disorder
- Post-traumatic stress disorder
- Alcohol and drug abuse
- Side effects of some drugs, such as diet pills and decongestants
How To Get To Sleep
For those of us who suffer from insomnia, restless nights can be exhausting and frustrating. Here are some tips for getting to sleep. Talk to a doctor or see a sleep specialist if you think you have a sleep disorder.
- Take a warm bath or shower before bed
- Exercise several times a week, avoiding the evenings
- Keep your bedroom quiet, dark, and cool
- Establish a regular sleep routine, getting up at the same time each morning
- Read something relaxing, or listen to soothing music
- Only lie down when you are ready to go to sleep - not while eating, studying, or watching TV
- Avoid stimulants such as coffee, tea, chocolate, and cola drinks
- Mangoes, sweet potatoes, bananas, persimmons, rice, bean sprouts, and nuts stimulate the production of serotonin and are sleep-inducing
- Don't eat a heavy meal before sleep, or go to bed to hungry
- Avoid alcohol - it can prevent the REM phase of sleep
- Expose yourself to an hour of morning sunlight
Some Audio to Set the Mood for A Good Night's Sleep
Why We Want To Sleep In The Afternoon
Some cultures shut down for an afternoon siesta to break up the workday. Why do we want to sleep in the afternoon? There may be science behind the afternoon siesta. After we eat, the body produces leptin, making us feel full. It also inhibits the production of hypocretin, which is produced in the brain and helps keeps us awake. This increases our feeling of drowsiness. If you are tired after lunch, you are not alone. Some famous afternoon nappers were Bill Clinton, Margaret Thatcher, and Winston Churchill.
All human beings are also dream beings. Dreaming ties all mankind together.
Jack Kerouc
What Are Dreams?
We spend more than 2 hours a night dreaming. Dreams don't just belong to humans - most mammals and birds also show signs of REM sleep, which is when dreaming usually occurs.
Why do we dream? When we are awake, our 5 senses are bombarded with information and images that are sent to the brain. While we sleep, our brain generates images without these external inputs. That is why we can do things that defy the natural laws, such as flying. Some experts believe our cortex is trying to make sense of random signals received during REM sleep. A story is being created out of fragmented brain activity.
Strong experiences and impressions can influence what we dream about, such as nightmares in those who have witnessed the atrocities of war or who have been the victim of a violent crime. A portion of our dreaming could be linked to thinking, which is why we sometimes find solutions while we dream. One study linked dreaming to retaining certain mental skills. People taught a skill and then deprived of non-REM sleep could later recall it; those deprived of REM sleep could not.
More On Sleep
- Nova - Sleep
A video connecting sleep and memory. - What is sleep?
The BBC looks at the science of sleep. - Dream Facts
15 facts about dreams. - How to fall asleep.
42 tips on falling asleep. - Sleep facts.
40 facts about sleep.