What is sleep?

We all know what sleep is, but on doing some googling I found the perfect official definition of sleep. Sleep is defined as a condition of body and mind such as that which typically recurs for several hours every night, in which the nervous system is relatively inactive, the eyes closed, the postural muscles relaxed, and consciousness practically suspended.

Sleep Cycle

According to the Sleep Council UK, during sleep our heart rate drops, our body temperature falls and we experience complex changes in brain activity.

An EEG (electroencephalogram) gives us an insight into the brains electrical activity when we sleep:

During sleep our heart rate drops, our body temperature falls and we experience complex changes in brain activity. An EEG (electroencephalogram) gives us an insight into the brains electrical activity when we sleep:

When we first fall asleep we enter non-rapid eye movement (NREM) sleep. NREM is divided into three stages: – NREM1 – NREM2 and – NREM3, each stage becoming progressively ‘deeper’.

Stages 1 and 2 are light stages of sleep from which we can be easily roused.

Stage 3 is a deeper stage of sleep from which we’re more difficult to rouse, and some may feel disorientated if woken from this stage of sleep.

Generally, after going through the NREM stages, we enter stage 4 which is known as rapid eye movement (REM) sleep, which the EEG shows as being similar to wakefulness or drowsiness. It is during the REM stage of sleep that we dream.

Each cycle lasts around 1½ hours and we need to experience all four stages in order to wake up rested.

A good night’s sleep consists of five or six cycles, whereas disturbed sleep consists of far fewer.

Sleep is largely controlled by sleep pressure, and the circadian rhythm, or our body clock, which is a 24 hour cycle that regulates all our biological and physiological processes. It anticipates environmental changes around us so that our bodies can adapt to them.

In ideal situations, the circadian rhythm will naturally rise in the early morning, promoting wakefulness and alertness, and will reach a peak in the evening. After a waking period of around 15 hours the pressure to sleep becomes greater and greater, in other words, we get tired. With the onset of darkness, the circadian rhythm drops to the lowest level and helps to maintain sleep.

To ensure you experience good sleep it’s essential to follow good lifestyle habits and to eliminate the factors that are causing you disturbed sleep. For example making sure that your bedroom is the right environment, looking at the lighting in your home, and avoiding foods and drinks that can hinder sleep.

How much to sleep?

The amount of sleep each person needs depends on many factors, including age. Infants generally require about 16 hours a day, while teenagers need about 9 hours on average. For most adults, 7 to 8 hours a night appears to be the best amount of sleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day. Women in the first 3 months of pregnancy often need several more hours of sleep than usual. The amount of sleep a person needs also increases if he or she has been deprived of sleep in previous days. Getting too little sleep creates a “sleep debt,” which is much like being overdrawn at a bank. Eventually, your body will demand that the debt be repaid. We don’t seem to adapt to getting less sleep than we need; while we may get used to a sleep-depriving schedule, our judgment, reaction time, and other functions are still impaired.

Benefits of Sleep

A good sleep helps in improving our health, mood and sex life. It also helps in maintaining the body weight.

Better health

In a study a link has been found between insufficient sleep and some serious health problems, such as heart disease, heart attacks, diabetes, and obesity. One study simulated the effects of the disturbed sleep patterns of shift workers on 10 young healthy adults. Just after four days, three of them had blood glucose levels that qualified as pre-diabetic.

Weight Control

Lack of sleep can make you put on weight by drastically slowing your metabolism down, according to a study by scientists at Uppsala University in Sweden. The researchers suggested getting plenty of sleep might prevent weight gain.

Read more about foods and vegetables that help in losing weight.

Increased Lifespan

Regularly sleeping less than you should is associated with a shorter lifespan, although it is not clear whether little sleep is the cause, or an effect of other illnesses. Studies have found people who routinely sleep for fewer than six hours a night have a higher risk of dying sooner than people of a similar age who sleep for seven or eight hours a night.

Lower stress Levels

Sleep helps in reducing stress levels, and with that people can have better control of their blood pressure. It’s also believed that sleep affects cholesterol levels, which plays a significant role in heart disease.

Read about foods which can lower cholesterol.

Better immunity

In a study, the sleep habits of 150 people were monitored for two weeks, after which they were exposed to a cold virus. People who got seven hours of sleep a night or less were almost three times as likely to get sick as the people who got at least eight hours of sleep a night.

Stay away from depression

A lack of sleep can contribute to depression. A good night’s sleep can really help a moody person decrease their anxiety. Sleep helps in achieving more emotional stability.

Are you anxious? Tips to reduce anxiety

Control Inflammation

Inflammation is linked to heart disease, stroke, diabetes, arthritis, and premature aging. Research indicates that people who get less sleep—six or fewer hours a night—have higher blood levels of inflammatory proteins than those who get more.

A 2010 study found that C-reactive protein, which is associated with heart attack risk, was higher in people who got six or fewer hours of sleep a night. People who have sleep apnea or insomnia can have an improvement in blood pressure and inflammation with treatment of the sleep disorders.

Better memory

It has been found out, that while we sleep, our brains process and consolidate our memories from the day. If you don’t get enough sleep, it seems like those memories might not get stored correctly — and can be lost.

Look attractive

Regular shut-eye actually makes you look healthier and more attractive, according to a 2010 study published in the British Medical Journal. Researchers photographed 23 people after a period of sleep deprivation and after a normal night’s sleep of eight hours. The photos were shown to 65 people who rated each photo based on health attractiveness and tiredness. The sleep deprived group scored lower in all three categories.

Clear thinking

Sleep loss affects how you think. It impairs your cognition, your attention, and you’re decision-making. Studies have found that people who are sleep-deprived are substantially worse at solving logic or math problems than when they’re well-rested. They’re also more likely to make odd mistakes like leaving their keys in the fridge by accident.

Better sex life

According to a poll conducted by the National Sleep Foundation, up to 26% of people say that their sex lives tend to suffer because they’re just too tired. There’s evidence that in men, impaired sleep can be associated with lower testosterone levels. The 2010 Sleep in America poll found about 20-30 per cent of men and women felt their family life and sexual relationships had been affected by their sleepiness.

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Read more about foods, which can help you have a good nights sleep.

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