Dreams and sleep cycles

dream phases

Many people mistakenly think that when it comes to falling asleep, the entire body enters a period of lethargy. in which the person sleeps. However, during all the hours of sleep, several processes will occur that have the objective of leaving the body as new. Sleep will go through a series of phases in which various processes occur.

In the following article we will talk to you in more detail about everything related to sleep and of its phases or cycles.

the sleep cycle

The sleep cycle will go through different phases throughout the night. Sleep is cyclical and each cycle will last about 90 minutes or so. These cycles repeat depending on the hours the person spends sleeping. The more hours slept, the more cycles the person will have. Within each cycle there are a series of well-differentiated phases or stages:

  • 1 phase: Numbness
  • 2 phase: Light sleep
  • 3 phase: Transition
  • 4 phase: Deep sleep
  • REM phase: paradoxical dream

circadian rhythm

The circadian rhythm is the biological rhythm that all living beings have and that allows the regulation of rest. The normal thing is that there is a certain synchronization with the environmental element, however there are times when there is a mismatch, such as in the case of the person sleeping during the day because of work or because of jet lag.

For the aforementioned sleep cycles to be fulfilled, it is very important to respect the circadian rhythm. It is therefore that when it comes to resting well and in an optimal way It is good to follow a good routine. Not having a routine can cause the circadian rhythm to suffer a great imbalance and the person does not rest well at all.

The importance of melatonin and cortisol at bedtime

Hormone production has a direct relationship with the circadian cycle. Some hormones are secreted while the body rests as is the case of growth hormone or cortisol.

Cortisol along with melatonin is essential when it comes to ensuring that the body is able to regulate rest. If melatonin is high, the body asks for sleep and rest. If cortisol goes down and up, the body is prepared to perform throughout the day.

Cortisol is the hormone that is formed in response to a person's stress level. Cortisol drops as night comes and rises early in the day. Melatonin, on the other hand, rises at bedtime and allows the person to fall asleep and sleep. In recent years, it has become very fashionable to take some melatonin to be able to fall asleep as soon as possible.

sleep cycles

The phases of the dream

As we mentioned above, sleep cycles They usually last about 90 minutes or so, repeating itself during the time the person spends asleep. The normal thing is to chain four or six cycles per night. Next we are going to talk to you in more detail about the different phases of sleep and their characteristics:

First phase: Numbing

This first phase includes the first minutes after the person falls asleep. This is the phase between wakefulness and sleep.

Second phase: light sleep

In this second phase the body gradually disconnects and breathing slows down along with the heart rate. The second phase usually lasts half a cycle, or about 40 minutes or so. It is difficult to wake up during this stage of sleep.

Third phase: transition

The third phase is quite short and It usually lasts no more than three minutes. In this phase the body is totally relaxed and disconnected. In the third phase, the famous growth hormone is usually produced.

Fourth phase: deep sleep

Deep sleep will occupy 20% of the sleep cycle. This is the most important phase of all and this phase depends that the quality of sleep is better or worse. In the fourth phase, breathing and arterial rhythm are quite low.

REM phase: paradoxical sleep

The REM phase is the most well-known or popular phase. During this stage a large number of rapid eye movements occur. It occupies almost 25% of the sleep cycle and usually lasts about 20 to 30 minutes or so. Brain activity in the REM phase is quite high and important. During this stage the person is dreaming, managing to capture information from outside.


light sleep and deep sleep

The first three phases of the sleep cycle usually correspond to light sleep while the last two The body enters what is known as deep sleep.

The normal thing is to enter said deep sleep around the time of falling asleep. If the person wakes up during the last two stages, the body does not fully recover and wakes up somewhat dazed. During the first two phases of sleep it is much easier to wake up.


We must start from the fact that everyone dreams, regardless of whether they remember the dream or do not remember anything. The normal thing is that the dream lasts a couple of hours within the entire sleep cycle. It is proven that dreaming helps the body process all emotions much better. What you experience throughout the day will have a direct impact on what you dream about while you sleep.

Most people who suffer from anxiety or stress during the day often suffer from nightmares at bedtime. Dreams can occur during all phases or stages of sleep. although the most vivid experiences occur in the REM phase. Some people can dream in colors and other people usually dream in black and white.

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