The study of sleep allows us to analyze its structure and classify it according to its characteristics: duration, interruptions, induction time… we will get very different patterns: insomnia, hypersomnia, and parasomnias (fragmented sleep). It is necessary to monitor the patient during a night of hospital stay to detect alterations in polysomnography records.
During sleep cycles of about 90 minutes are repeated, and can occur between four and six cycles during the night. In each cycle four phases follow one another:
- Phase I or numbness: lasts 10 minutes. It involves superficial relaxation.
- Phase II or light sleep: lasts about 45 minutes. It is a phase of disconnection with great brain activity by which it allows us a sudden awakening before an explosive experience.
- Phase III or disconnection: lasts 2 minutes. It involves deep relaxation.
- Phase IV or Delta or slow sleep: lasts 20 minutes. Determines whether or not the sleep has been restful.
- REM sleep phase: lasts 25-30 minutes. It is characterized by rapid eye movements and high brain activity being able to capture external activity. It is the phase in which we dream and remember what we dreamed.
Depending on age, the physiological need for sleep is variable. From the age of 30, there is a slow and progressive decrease in the amount and quality of sleep. There are influential situations: stress, hormone levels, seasons, physical activity…
Tips for better sleep
It is a lot of pathologies associated with sleep, as we will see later. Therefore the great importance of enjoying a good amount and quality of sleep. Our feeling of rest upon awakening will favor daytime activity, the balance of our hormonal rhythm, the maintenance of our immune system on alert, our ability to respond quickly and activated, and our musculature in a state of optimal muscle tone.
To improve your sleep you can follow some of these tips:
- Hourly discipline: go to bed and get up every day at the same time.
- Flattering environment: comfortable, no noise or light.
- Care for habits: do not drink stimulating drinks or alcohol in the evening hours, do not dine copiously, do sports in the afternoon (not just before bedtime), prepare for sleep (relaxation, infusion, reading, hot bath), avoid naps, and get into bed when we already have a feeling of sleep.
Most common sleep disorders
Insomnia is the difficulty of falling asleep or maintaining sleep causing the impression of not having had a restful sleep and affects one-third of the adult population. It negatively affects the patient causing lack of concentration, mood alterations, apathy, fatigue, increased response time to stress situations…
Insomnia is one of the main sleep disorders and involves an alteration in the quality and/or quantity of sleep for at least 3 days a week and for several months.
Although it may have an organic base associated with some diseases, insomnia is very common related to the intake of stimulating substances (coffee, tea, cola, cocoa…).
Hypersomnia refers to excessive daytime sleepiness. It involves an inability to stay awake so it greatly affects the quality of life. There are diagnostic tests that quantify the difficulty of the individual in maintaining wakefulness.
Within hypersomnia, there are two high-impact entities: narcolepsy and sleep apnea syndrome.
- Narcolepsy is excessive daytime sleepiness and cataplexy (sudden and reversible loss of movement ability). People who suffer from it move very quickly from the Waking State to the REM (deep) sleep phase.
- Sleep apnea syndrome consists of episodes of apnea (breathing pauses) during sleep with the consequent fragmentation of sleep.
Parasomnias are disorders of behavior or behavior during sleep. They can occur upon awakening or during sleep.
Upon awakening, we may encounter the so-called “confusional awakening” or feeling of dislocation and disorientation that can last from a few minutes to hours. It is more common in young adults and usually disappears with age.
During sleep, we can encounter sleepwalking and night terrors. Sleepwalking is defined as the sequence of complex behaviors, including walking, during which the subject is deeply asleep. Waking up does not remember the episode. It is more common in childhood and tends to disappear with age. As for night terrors, they are characterized by the sudden appearance of episodes of crying or screaming with a sense of fear during the phases of deep sleep. It is typical of childhood.