Why Do We Sleep?

Did you know that humans spend nearly a third of their lives asleep? Perhaps not. I’m sure that we’ve all asked ourselves that “why do we need sleep”.

To be precise, there’s no correct answer for why do we sleep but there are several possible reasons which might help us reach a collective conclusion.

Have you ever disappeared from social media to take some time off of it? If yes, then sleep is a similar phenomenon. It is an offline mode for the brain to escape from the reality and take a break to rest the exerted brain cells and nerves from functioning all day.

A more complex and scientific explanation to why we sleep is that sleep is the way of the brain’s ability to reorganize itself. This process is called plasticity.

Other Reasons:

  1. Energy Conservation: Sleep is paramount for restoring the energy lost during the whole day. Sleep is your body’s way of relaxing tensed muscles of the brain, optical nerves, and limbs. That is the reason why we feel good and energized after a good sleep!
  2. Cellular Restoration: During sleep, tissues grow, muscles get repaired, hormones are released and protein synthesis takes place. All these biological processes are substantial for proper functioning of the body.
  3. Brain Functioning: Sleep reduces all kinds of toxins from the brain and disposes the waste from the nervous system. This enhances processes of problem-solving, creativity, decision-making, memory, and concentration.
  4. Weight Maintenance: Sleep regulates our weight by controlling hunger hormones. Lack of sleeps makes your hungrier, and you gain weight.
  5. A Healthy Heart: Healthy sleep decreases high blood pressure, inflammation, elevated cortisol levels and insulin resistance making your heart healthier.
  6. Better Immune System:Getting proper sleep, scientists have found, seems to help our immune systems function best. While our body is resting, immune cells known as T-cells spend that time racing around our bodies. Other immune cells also work better with more sleep.

How much sleep do we need?

The amount of sleep that an individual needs either depends upon his/her age group of medical condition. For instance, an adult needs 7-9 hours of sleep per night, one-year-olds roughly need 11 to 14 hours for sleep, and teenagers need 8-10 hours of sleep.

Individuals suffering from chronic mental illness like anxiety disorder or clinical depression might need more sleep than usual owing to medications.

A sleeping pattern for a healthy human is:

  • Birth to 3 months: 14 to 17 hours
  • 4 to 11 months: 12 to 15 hours
  • 1 to 2 years: 11 to 14 hours
  • 3 to 5 years: 10 to 13 hours
  • 6 to 13 years: 9 to 11 hours
  • 14 to 17 years: 8 to 10 hours
  • 18 to 64 years: 7 to 9 hours
  • 65 years and older: 7 to 8 hours

What happens when we sleep?

Some people think that when sleep is a way of the brain to stop functioning and take rest. It is completely incorrect and misleading as the brain can never stop working. When we sleep, the brain processes unconscious or subconscious thoughts and weaves them into dreams. Along with that, the mind gets restructured as the toxins from the nervous system get removed.

A human body cycles through four stages of sleep. The pattern typically repeats itself every 90 minutes. This implies that the stages will repeat about 4 to 6 times during a 7- to 9- hour sleep period. The pattern includes three phases of non-rapid eye movement (NREM) sleep and one phase of REM sleep.

What happens when we do not sleep?

Today, almost every one faces sleep deprivation once in a while. This can be caused under prolonged stress, or more severe conditions like mental illnesses (anxiety, depression, behavioural dysfunction, post-traumatic stress disorder etc.).

Daily personal and environmental stressors like bad day at work, unstable eating patterns, examinations, fight with a loved one and so on can keep an individual up at night. However, the fact that it happens to everyone does not mean that it is healthy. As stated above, a healthy 7-8 hour sleep is extremely significant for biological, physical, emotional, psychological and mental well-being of an individual.

When you don’t sleep during the day, you feel sleepy the next day. You feel lazy, unmotivated, fatigued, and irritated. In fact, a recent poll taken by the US National Sleep Foundation illustrates the magnitude of this problem. 20% of American adults report being so sleepy during the day that it interferes with their daily activities at least a few days per week, and a frightening 17% report falling asleep while driving within the last year. The risk of sleep-related accidents is compounded by the fact that people are unable to judge the likelihood that they will fall asleep, and by the related misconception that falling asleep is a slow process. Apart from this, sleep deprivation can cause long or short memory impairment which can further take a horrible transformation into amnesia.


If you are finding it difficult to sleep at night, you can try listening to soft, melodious music or reading a book. This calms your never cells and relax your mind. If you still can’t sleep, it is time you consult your therapist! Sleeping is as substantial as eating, drinking and working. Compromising with your sleep means compromising with your health.

Do check out as to why do we yawn and let us know what you think about it in the comment section!