Adult normal need 8 hours a night, the child is at least 10. Much time is required for the body to recover spent the day energy, gain strength for the next day.

Fatigue, weakness, drowsiness, nervousness occur on the second day when lack of sleep and insufficient rest.

The short duration of sleep and downed the mode of the day can lead not only to a harmless distraction, but also threatened dire consequences for health. Insufficient night's rest, over time, causes an increase in blood pressure, change in blood sugar levels, increase levels of stress hormones, decrease the amount of leptin (a hormone that suppresses the appetite). By the way, the workers of night shift because of what is happening in their body changes caused by lack of sleep, often supported by high-calorie food, feel the need for sweets without apparent need. And this is promotes weight gain, increases the risk of developing diabetes.

But it's not all negative consequences. Lack of sleep leads to vulnerability of the body from inflammatory processes in organs and tissues, reducing the level of immunity. This is because only during sleep the adrenal glands produces hormones corticosteroids (which have anti-inflammatory effect). The maximum number is formed only in the morning. But if the regime lost, and the morning is for the biological clock of the body does not occur or is significantly shifted, and then hormone production will remain at a low level. As a consequence of colds, inflammation, SARS.

Neurologists warn about one of the important features. So, sleep not only promotes recovery of strength and energy, but also enhances memory, allows you to capture and organize memories. During a night's rest, the human brain is constantly working, keep it in memory the most important information. That is why a full good night's sleep is important for creation of ideas, designs, inventions, artistic and scientific activities, and most importantly – it contributes to strengthening the knowledge, brilliant examinations, productive health.