Why Do We Sleep?

Sleep is a condition of the body and mind that happens for several hours every night, mostly in which a major part of the nervous system is relatively inactive along with the closure of the eyes, switching off of the sensory input, decrease in the appreciation of hearing, partial suppression of other senses like touch and smell, relaxation of the postural muscles and practical suspension of consciousness.

Normal life processes like sleep is as important as any other vital process like breathing, eating etc. Nearly half of one’s life is spent in sleeping if one has to have good health. Sleep is not a mere inactivation of wakefulness but many other vital functions of the brain take place during sleep.

As mentioned above, sleep has functions apart from just the suppression of one’s consciousness. Here are some of the bodily processes that take place while sleeping:

1.              Energy Conservation – As sleep is a phase of inactivity, the energy reserves are out of use and are kept for future use. ATP (Adenosine Triphosphate), the energy molecule production occurs as a result of uninterrupted food digestion and metabolism but the use of it is limited so as to be used during daytime activities. Though there is some energy consumption during digestive processes, breathing, heart functions and other vital functions.

2.              Repair / Restoration – Repair of any damaged tissues and the overall growth process occurs at night time. The release of growth hormones is to the maximum at night during sleep. The growth hormone along with other hormones like thyroid hormone, testosterone, cortisol etc., are involved in the growth and repair processes. It is very essential for one to sleep optimally to have a healthy growth and repair trajectory of the damaged or worn-out tissues in the body.

3.              Information Processing and Memory Consolidation – Wakefulness is burdened with a lot of inputs from the eyes, ears, skin and other senses. It is not feasible for the brain to process the information to segregate the information into important and unimportant. Also, once the information which is important decided either by repetition or personal experience of the person, it is stored as memory. Most of this process occurs on the hippocampus, a part of the brain.

4.              Immune Regulation – As mentioned above, due to a part of brain going into rest, the remaining part concentrates on homeostasis in many vital aspects. Immunity is one such process, wherein the production of white blood cells (WBCs) occurs as a part of replication which is nothing but growth in a sense. These WBCs play a vital role in immunity which is our resistance power towards foreign antigen; such antigens could be a virus, bacterium etc.

5.              Mood Regulation – The release of most of the hormones is at its peak during sleep. Some of them include stress response and stress alleviating hormones. These hormones either push away the inhibiting stimulus or overcome the negativity created by the external thought stimuli. This in-turn elevates one’s mood and keeps one fresh of mind after a night’s sleep.

6.              Synaptic Regulation – Synapses are junctions between the nerves in the central nervous system (The brain) and peripheral nervous system (peripheral nerves). These are the places where the information is conveyed from one nerve to another in the process of conduction of information. The information flows in both directions from sense organs and other tissues to the brain and from brain to these organs, muscles etc. The information transfer occurs in the form of movement of chemical neurotransmitters from one nerve to the other. During sleep, the neurotransmitter balance is maintained, freeing the nerve junctions from residual chemical neurotransmitters which might interrupt or intervene in a healthy information transfer.

7.              Waste Clearance – Due to the peak production of hormones involved in metabolism, many such processes take place where detoxification and the removal of the waste and hazardous chemicals occurs. Either these processes occur via the liver and thrown out through feces or filtered in the kidney through urine. Hence, good health needs good sleep.

8.              Brain Maturation – This in a sense is the processing of all the information and experiences, keeping it available for future encounters with such stimuli. It is a way of learning how to grow in the outer world. The information is analyzed and suitable responses are being formulated which depends on our hormone profile and other inputs in our life. This makes our character unique and makes us what we are.

9.              Circadian Rhythm – It’s a rhythm which needs no clock but performs as one. Regular sleep timing is essential to stick to the clock which involves the release of specific hormones at specific times as per the requirement of the body. This makes the metabolism follow a pattern and function smoothly without any confusion.

10.           Dreams – A fantasy in which a part of sleep is spent but it isn’t one. Dreams are nothing but a process where the information in the brain is processed. The inputs to this process is via experiences and thoughts. The validity of them is not certain. Some information passes through a partly conscious part of the mind, projecting it as a dream. Some have meaning some do not. It is their relevance to reality which frames one’s character.

A doctor is most of times asked, “What happens if we don’t sleep enough?”, “What happens if we take sleeping pills?”, “I am not getting enough sleep?” or “I am working in shifts; is it dangerous?”

The answer to these questions is precisely what is explained above. If we do not sleep enough, many of the vital processes discussed above do not occur well, causing health problems.

If one gets addicted to sleeping pills or consumes them more, the natural processes that occur during the natural sleep do not occur to their optimal level. Sleep is a voluntary process by the brain which decides when to sleep. If forced with sedatives, though the consciousness drops down, the processes which occur during natural sleep do not occur and the person is for sure at a loss.

Not getting enough sleep, not only disturbs the vital hormones and the normal body metabolism, it also affects one’s mood, brain maturation, dreams etc. These processes decide a person’s character. Hence, one can go into depression or any other form of psychological problem.

Working in shifts is one situation where one has to disturb their circadian rhythm. It is not advisable. Yet, in unavoidable circumstances, it has to be made sure that the brain is given time to adapt to the rhythm we want. Sudden changes in the rhythm due to short shift postings is not safe at all. A minimum of month or more is needed for one to get adjusted to the new shift and avoid sudden movement into other shifts.

Sleep is a vital process of the body. It is not just rest or dreams. It is an essential process which must be given to the brain for optimal mental and physical health.