A person spends a third of his life in a state of sleep. In some animals - for example, in the feline family - the proportion of time devoted to sleep is more significant. Each animal has a specific posture taken in a dream; a person prefers to sleep in a lying position.
It also happens that a person falls asleep while sitting. This happens to those who did not go to bed on time, stayed too long at work or in front of the TV. But such a dream does not give a proper rest, after which a person feels overwhelmed and sleepy. It seems that sleeping in a sitting position is contraindicated for a person.
The harm of sleeping in a seated position
The need to sleep lying down is associated with upright posture inherent in humans. While awake, people are in an upright position, maintaining which requires significant muscle tension. In addition, in this position of the body, the force of gravity affects it more strongly. The area of contact with the atmospheric air above the body is much higher in a bipedal creature than in those animals that move on four limbs, therefore, the pressure exerted by the air column on the human body is quite large. This puts a lot of stress on the spine.
In order to withstand all these colossal loads during life, the human body must periodically rest from them. This is possible only when the person assumes a recumbent position: the muscles relax, the effect of gravity and the pressure of the air column decreases.
Some people prefer to sleep while sitting. This is what, for example, Salvador Dali did. But this case can be called an exception that confirms the rule: Dali's paintings are characterized by strange, bizarre images, bordering on madness, reminiscent of nightmares. Possibly, bad sleep, associated with the habit of sleeping while sitting, played an important role in the formation of this attitude. It is not worth following the example of the great artist: masterpieces may not be created, and the nervous system will certainly suffer from chronic lack of sleep.
To whom is it harmful to sleep lying
Still, there are people who are not recommended by doctors to sleep while lying down. We are talking about those who suffer from cardiovascular diseases. Due to some features of the human circulatory system, in the supine position, the flow of venous blood to the heart increases. This situation requires an increased supply of oxygen to the heart. A healthy cardiovascular system successfully copes with this, but with coronary heart disease, when the blood supply to this organ is impaired, a lack of oxygen can provoke an attack of angina pectoris or even a heart attack. A heart attack in a state of sleep is especially dangerous, because a sleeping person cannot take medicine or call for help. Sometimes such patients die of a heart attack without waking up.
Of course, it is also impossible for such patients to sleep while sitting, but they are advised to sleep in a semi-sitting position: their legs are extended, the body is thrown back on the pillows at an angle of about 45 degrees.