"Sleeping is not resting and much less wasting time"

2001/07/06 Mendiburu, Joana - Elhuyar Zientziaren Komunikazioa

• Anatomia/Fisiologia
• Osasuna

Sleep changes with age and customs

The hours they sleep and the dream itself changes with age. A newborn, for example, sleeps 18 hours and also has many small sleep/awake cycles. Over time cycles and hours of sleep are reduced. Teens sleep about 9 hours and adults 7.5 hours. Over the years, in old age sleep loses effectiveness and it is enough to sleep 6.5 hours.

However, do not think or want to sleep 8 hours a day. This is the most common, but there are those who have to sleep 6 hours and others who need more than 9 hours. After all, the next day best reflects whether you have fallen asleep enough or not.

On the other hand, to know if a person's dream is good or not, it is necessary to know their habits. Medical history, sleep related habits (how many hours sleep, when they lie down, if there are changes in rhythm...), if you take medicines, if there are allergies or other factors that alter the respiratory rhythm, if you have infections or pain...

Phases of sleep

Sleep is divided into five phases. The first phase is the time it takes for the body to adapt before bed. Normally this phase usually lasts about 10 minutes, that is, only 5% of the duration of sleep. In this phase the body relaxes, breathing becomes uniform and brain activity decreases.

The second phase is the transition phase. This phase spans a long time, about 50% of sleep.

Phases 3-4 are similar and are the phases of deep sleep. Each of these two phases lasts 60-70 minutes. In these phases strong tactile or acoustic stimuli are needed to wake up.

The final phase is the so-called REM (Rapid Eye Movement). We always dream in the REM phases, but we only remember that we were dreaming when we are in the REM phase.

Phase 1, 2, 3-4 and REM follow ups are cycles of 90 to 100 minutes. These cycles are repeated between 4 and 5 times in the hours of sleep, since despite having the feeling of having slept 8 hours in a row we always wake up between 6 and 8 times. These awakenings are usually very short – less than 30 seconds – and may not be aware of it. However, cycles are not always complete. In the first half of the night we slept more deeply and in the second half, the REM and 2 phases are more common.