Loneliness

The first purpose of sleep is restoration.

Every day, your brain accumulates metabolic waste as it goes about its normal neural activities. Sleeping restores the brains healthy condition by removing these waste products. Accumulation of these waste products has been linked to many brain-related disorders.

The second purpose of sleep is memory consolidation.

Sleep is crucial for memory consolidation, which is responsible for your long term memories. Insufficient or fragmented sleep can hamper your ability to remember facts and feelings/emotions.

REM, the Rapid Eye Movement stage of sleep happens when our eyes are moving fast; we are said to be dreaming in that stage.

NREM (Non-Rapid Eye Movement) is the stage of sleep when we are in deep sleep and are not moving. In this stage, our brain is able to clear toxins and consolidate memories.

Sleep, according to deep research on flies, has a function of reversing the ancient biochemical process of oxidation. Without sleep, there is no restoration possible.

Sleep studies prove it is worse than starvation, as early studies (19th century) conducted on puppies showed that they died in about five days if deprived of sleep and kept in motion.

... or ROS is a molecule that builds up in the intestines of animals that are denied sleep.

• Studies conducted on fruit flies and mice showed rising levels of ROS when kept in sleep deprivation.

• Antioxidants, when given to sleep-deprived flies, made them healthy and active again, proving that the artificial restoration is possible.

Dreaming accounts for 20% of our sleeping time.

The length of dreams can vary from a few seconds to almost an hour. During REM sleep, the brain is highly active. The muscles are paralyzed, and the heart rate increases. Breathing can become erratic. 

Although eight hours is the common mention, optimum sleep can vary from person to person and from age to age.

One review that worked through 320 research articles concluded 7 - 9 hours of sleep are enough for adults. According to experts, too little or too much sleep can both have a negative impact on your health.

It's based on the idea that by partitioning your sleep into segments, you can get away with less of it.

Though it is possible to train oneself to sleep in spurts instead of a single nightly block, it does not seem possible to train oneself to need less sleep per 24-hour cycle.

Caffeine works primarily by blocking the action of a chemical called adenosine, which slows down our neural activity, allowing us to relax, rest, and sleep.

By interfering with it, caffeine cuts the brake lines of the brain’s alertness system. Eventually, if we don’t allow our body to relax, the buzz turns to anxiety.

Cellphones, tablets, and all kinds of personal electronics are not a good idea when you’re getting ready for bed.

Researchers have increasingly focused on “blue light” emitted by screens and its effect on sleep and negative sleep-related health outcomes.

Our bodies tend to follow a natural rhythm of wakefulness and sleep that is attuned to sunrise and sunset for a reason.

While some missed sleep here and there isn’t necessarily a big deal, shifting your sleep schedule long term isn’t healthy.

It is exactly during times of social uncertainty and anxiety, when we need sleep the most, that it is most disrupted.
We need sleep for maintaining the immunological function, which is key to preventing and recovering from infectious diseases (like the one created by the new virus).

• Anxiety over the future and fear for the health of loved ones increase hyper-arousal and rumination, thus intensifying insomnia.
• Isolation from regular social rhythms and natural light will mess with our body clock, confusing us about when we are supposed to feel tired and when to perk up.
• The smartphone age has already led to a substantial deterioration in both duration and quality of sleep.

Although it is recommended that healthy adults should aim for seven to nine hours of sleep, everyone is different. There are people who need just three to four hours to stay alert. 

If you’re not sure how many hours of sleep you need on a daily basis, experimentation is the best way to go. Try waking up without an alarm and figure out what your natural wake-up time is. Observe how adding or subtracting one hour of sleep impacts your productivity.

The harm of bingeing on sleep on Saturday and Sunday is that it makes it hard to get a full and well-constructed night of sleep on Sunday night, which then sends us off into the workweek on the wrong foot.

If you don’t try to wake up at a similar time at the weekend, it is similar to giving yourself jet lag every weekend.

• Various studies point out that sleep influences two appetite hormones, leptin (to decrease appetite) and ghrelin (to stimulate appetite), which is also known as the hunger hormone.
• Lack of sleep is associated with higher levels of ghrelin and lower levels of leptin, making the person more likely to overeat.

• Sleep-deprived people crave for and also end up eating more carb-rich foods and sugar.
• Sleep duration affects the release of insulin in the body, that affects our glucose levels, and prolonged sleep deprivation can lead to obesity and type 2 diabetes.
• Research shows that exercise prevents the damage done by lack of sleep and also makes one eat less.

To stay healthy, one has to sleep more and also do regular exercise.