The Importance of Sleep and the Different Sleep Stages

Most people know that sleep is an essential bodily function that affects every facet of our health. However, what really is sleep and why is it so important? To learn more about the importance of sleep and the different sleep stages, schedule an appointment with an English-speaking doctor at Medvisit!

Sleep is an altered state of consciousness, and, during this time, we have little interaction with our environment– depending on what stage of sleep we are in. There are four stages of sleep in total: one for REM sleep (rapid eye movement) and three for non-REM sleep (NREM). Each stage of sleep is characterized by differing brain activity and patterns, and they all have a unique and vital importance to ensure you remain healthy. These non-REM stages are interspersed throughout the night by REM sleep, sometimes referred to as dreaming sleep. While REM sleep rejuvenates the mind and is crucial for memory and learning, quiet sleep is necessary because it aids in body restoration. Let’s delve into what happens during each stage:


Stage 1

Stage 1, or N1, is the shortest stage of them all, typically lasting for around one to five minutes. This stage is more simply known as the “dozing off” stage, as the body hasn’t fully relaxed. However, the brain and body’s activity do begin to slow which can sometimes be accompanied by brief movements known as twitches. When observing brain activity during this stage of sleep, there are only small changes. Someone can be woken up in this stage but, with little distraction, they can easily move into the second stage of sleep.

Stage 2

Stage 2 of sleep is when the body enters a much more relaxed state which can be observed in physiological changes: relaxed muscles, a drop in body temperature, and a slower heart rate. Eye movements also stop, and brain activity slows with small moments of activity. These small bursts of activity actually help a person stay asleep as they block out external stimuli. This stage of sleep usually lasts between 10-25 minutes for the first sleep cycle but, as the cycle repeats itself throughout the night, this N2 stage can become much longer.

Stage 3

Stage 3 is characterized by deep sleep as it is much more difficult to wake a person up during this stage. Key physiological changes can also be observed in N3 such as a decrease in breathing rate and muscle tone. Perhaps the most identifiable aspect of this stage is the patterns in the brain activity known as “delta waves.” Scientists believe this stage is the most imperative for body restoration as it supports your immune system and growth and even contributes to creativity.

REM Sleep

The fourth and final stage of sleep is known as REM sleep, which stands for rapid eye movement sleep. As the name implies, brain activity increases during this stage and the eyes and breathing muscles can be observed moving rapidly. This stage of sleep is associated with more intense dreams, and certain areas of the brain are stimulated that are essential for learning. It gets longer as the night goes on; most people spend about 25% of their sleep in this stage.


In conclusion, each stage plays a vital function and contributes to the body’s overall health. However, people who suffer from insomnia, sleep apnea, and other sleep disorders may struggle to enter the deeper stages of sleep which can severely impact their health. There are several factors that can affect the sleep stage such as age, sleep patterns, temperature, exercise, and certain medical conditions.

If you feel you are suffering from a medical condition that is affecting your sleep such as sleep apnea, contact your doctor in Barcelona to discuss treatment options. You can always rely on Medvisit; we have the most reliable doctors in Barcelona who can help you with the most advanced medications and guidance. Appointments can easily be booked with knowledgeable and experienced English-speaking doctors where you can discuss underlying issues and achieve more restorative sleep.