Sleeping is often considered a superfluous activity in our society that works more and more 24 hours a day, 7 days a week, 365 days a year. There is so much to do, so much to achieve. We always want to do more, and we think we can always do more, forgetting our biological condition, the existence of physical limits and our basic needs as living beings. Our daily activities are no longer regulated by sunlight. Day or night, we are always connected in a virtual world, 24/24 hours. We forget that we have an internal clock and a specific need for sleep , which characterizes us as human beings. Although we seem to be free to choose what we want to do and when we want to do it, we often cannot stop and say no. What we do is try to trick our biological system, so that we do not feel sleepy. This is often unconsciously and with harmful consequences for health. Why do we sleep? Sleeping is a homeostatic need of our organism, which means that it allows us to maintain the balance of our biological system , just like eating or drinking. Each of us has a specific need for sleep, both in quantity and in preferred hour for sleep and awakening. These aspects must be made aware and respected by each one. We forget often that we sleep because we have a brain, that is, sleep is a function of the brain , like other neurological functions: language, memory, mobility, or sensitivity of one of the limbs. And like all other brain functions, it has specific neuronal circuits that are activated or deactivated to make sleep happen. Falling asleep, sleep itself, alternating between the different phases of sleep over the course of a night, consolidating deep sleep, protecting awakenings, and awakening itself have specific circuits underlying them, which are getting better and better known. However, sleep is a very particular brain function . Particularly because it is a function that has the goal of making the system that produces it much more efficient . We can say that sleep exists so that all other brain functions and all other organs can work more effectively and efficiently. Proof of this are the effects of sleep deprivation, both acute and chronic. In fact, lack of sleep affects the functioning of our own brain. All brain functions become less efficient when there is a sleep disturbance, whatever it may be, meaning that most of our brain functions, such as memory, attention, concentration, visual-perceptual, visuoconstructive capacities, ability to change strategies, abstract thinking, creativity, language, emotions or even motor skills depend on sleep. How much do we need to sleep? There will be people who feel perfectly well sleeping 6 hours a night, but others will need to sleep 10 hours, without this being a sign of laziness or illness, but a consequence of our genetic variability. Not all of us have blue eyes, not all of us have fair skin, not all of us are restored with 6 hours of sleep. In fact, most of us do not stay. We are different and we must continue to want to be different. We cannot sleep less, just because it makes us feel good and without consequences. And why do not we sleep as well as we would like? We often do not sleep well because we try to deceive our own biological system , many times without realizing that we are doing it: We are exposed to intense light emissions on fantastic monitors, when it is already dark outside. We consume stimulating drinks and foods throughout the day that make us avoid sleeping, namely decreasing the pressure for sleep (which accumulates throughout the day) and the amount of slow wave sleep. This is essential for us to have a natural fall asleep at a certain time and so that the next morning we have the feeling that sleep was restful. For many of us, coffee (even if it is taken for the last time after lunch) has this effect. We postpone meals until later (sometimes we dine at the time we should be falling asleep), unaware that mealtime also helps to synchronize our sleep-wake rhythm. We have activating activities at the end of the day, both physical and intellectual, when we should be gradually preparing our system to naturally turn off (because we do not have an on / off button and we do not sleep when we want to, but when we are ready to do it). At night, we watch television thinking that we have the right to relax a little at the end of a working day. Of course, we have! But not at the expense of hours of sleep. When we lie down, how often do we use those first minutes to think about what we must do the next day? In silence and without other external stimuli, this is an excellent way to get our brain to work, to self-activate it, to get it to do what it knows best: thinking. However, we should not do this at that time if the goal was to fall asleep and therefore allow brain activity to progressively shift from an awake to a sleep mode. Many hours before going to bed, we should have time to think about it and all the worries that plague us. We could, for example, have reserved period for concerns where, in the afternoon, we could think about our problems, difficulties, fears, plans, projects and order our priorities for the next day. And weekends, how many times are our bedtime and waking hours completely different from those we have during the week? It is as if we change time zones every weekend. Can you imagine traveling to New York every friday night, after a tiring week of work and returning to Portugal early in the morning on monday and immediately starting work again? It would be very difficult, most say, they would be on jet-lag ... But the truth is that without having left the country, many of us live in what we call a social jet-lag. What are the consequences of sleep deprivation? By not respecting our internal clock or sleeping less than we need to, we will not be respecting essential premises of our biology, that should not be modified. It means that we are becoming less efficient, contrary to what we often think. Trying to have a rhythm that is not ours will have heavy consequences , such as: Excessive daytime sleepiness; Changes in our cognitive abilities, namely in attention, reaction time, memory, ability to make decisions, mood; An increased risk of accidents. Sleep deprivation is also associated with an increased cardiovascular risk , endocrinological and metabolic changes which can make weight control difficult, and changes in immunity with an increased risk of infections. Chronic sleep deprivation can lead to a decrease in the sensation of drowsiness, maintaining, however, the neurocognitive and psychological changes associated with it. This fact helps to perpetuate sleep deprivation itself and an increase in the so-called “sleep debt”. On the other hand, the assessment that each of us makes about how we feel when we are deprived of sleep, may not be proportional to the real neurological effects of it (when these are measured objectively through different medical tests). This means that we may not get much sleep and have major changes in our performance, related to sleep deprivation. Author : Carla Bentes In the Hospital da Luz network, doctors of various specialties - neurology , pulmonology , otorhinolaryngology , pediatrician - in their specific areas of expertise and with differentiation in sleep medicine can help you in your sleep problem. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
