We all need sleep to properly function and live. Not getting enough sleep harms our well-being, health, and immunity. Even one sleepless night can affect our bodies. Today's times do not have a positive effect on proper sleep and its sufficient amount.
Work-related stress, irregular lifestyle, overwhelming responsibilities, or mental health problems do not help. People suffer from various sleep disorders. Their types are genuinely dizzy. Let's take a look at the most common of them is Sleep-Related Breathing Disorders.
Image Credit: Agnieszka Pregowska
Sleep Disorders
Actually, there is a broad range of sleep disorders; we can say that they are disturbances from normal sleep mode (five sleep stages, repeated five to six times per night [1]). All sleep disorders are classified into seven categories [2].
Still, in this article, we focus only on Sleep-Related Breathing Disorders [3] that relate to the transition from the state of light sleep to the state of deep sleep, where the relaxation of soft palate muscles and tongue follow. If the tissues in the throat (like the tongue) relax too much, vibrations appear and create a sound – snoring. When somebody has a narrower airway (consequently, the greater the force of airflow), it may contribute to the tissue vibrations increasing.
Sleep-Related Breathing Disorders and their variations
Sleep-Related Breathing Disorders are sleep disturbances related to abnormal breathing. They are divided into four sections. In practice, they frequently overlap or coexist with one another. Let’s take a close look at the first one – Obstructive Sleep Apnea (OSA). We can describe it as a losing ability to freely breathe.
Sleep apnea appears when there is an interruption in human breathing for at least 10 seconds. This dangerous situation may repeat during the night. In this time, our brain receives an alert! – which contributes to sleep interruptions to get some air. People suffering from OSA also snore most often. This may also lead to hypersomy (occurrence of drowsiness despite sleeping the night and prolonged sleep or episodes of sleep during the time devoted to activity) [4].
Another central disorder of hypersomnolence is daytime sleepiness. It can be caused by abnormalities of the neural system or by other medical conditions and substances. People affected by this disease suffer from excessive sleepiness. The most common central disorder of hypersomnolence is narcolepsy, which results in the loss of hypothalamic hypocretin (orexin) – a neuropeptide produced by a group of nerve cells found in the hypothalamus and brainstem, and its receptors are found in different regions of the brain [5]. When you have narcolepsy, you can suddenly fall asleep, or sudden loss of muscle tone and hallucinations when falling asleep, or just waking up.
Insomnia is a lack of sleep or very irregular sleep. We have difficulties with falling asleep and staying in this state [6]. This may lead to chronic fatigue and cognitive impairment. Stress or sadness can significantly contribute to this disease, but not always its symptoms are apparent. Untreated insomnia can even result in depression [4].
When we think about sleep conditions like sleep timing, disorders, which influence circadian rhythm sleep-wake disorders. This condition prevents us from regular sleep times during the night. This may be due to significant discrepancies between our circadian rhythms and the externally imposed social and work cycles [7].
The next group is parasomnias, which include abnormal movements, behaviors, emotions, perceptions, nightmares, night terrors, sleepwalking, confusional arousals, and many others during sleep [7].
Additionally, we also have sleep-related movement disorders. During which the whole body or a part of it is affected by the movement [8].
Image Credit: Agnieszka Pregowska
Sleep monitoring
A diagnosis of a specific sleep disorder is challenging. Sleep disorders lie snoring, wheezing, or sleep apnea do not depend on age; they can affect anyone. They mainly affect men, obese people with a high BMI, people who have had a stroke, have high blood pressure, or other heart conditions. And how can we diagnose them?
While sleeping, we may hear abnormal breathing, noises during sleep, or even sound with an almost explosive character (especially when the airways open after blockage). In emergencies, sleep monitoring is of high importance. We can do this professionally (polysomnography- full night hospitalization, in a special bedroom [9]) or at home, in a simpler or more complicated way.
The first one is costly and limited to availability. It includes monitoring of the neurophysiological signals derived from the skull, such as electroencephalography (EEG), electrooculography (EOG), and electromyography (EMG). The second can be done with a smartwatch, and the third deals with telemedicine and remote monitoring systems. Such a system enables data collection, analysis, and maintenance services [10].
We can remotely collect signals like heart rate, temperature, ECG, EEG, SpO2, GPS signal of patient’s position, and information from motion sensors. In the next step, these signals are analyzed by dedicated software, interpreted, and the necessary actions like alerts are commissioned. Algorithms for biomedical signals connected with sleep are still developed.
Tremendous efforts are undertaken to limit the number of signals (types) needed to recognize disorders early in their development, such as classifying sleep disorders based only on ECG signals [11]. But still, the most optimal sleep monitoring involves EEG, EOG, EMG, blood oxygen levels using pulse oximetry and the measurement with microphone and camera. And it is all time-consuming and complicated.
Summary
Sleep is a large part of our lives. Some of us sleep even half of their life. It plays a vital role in human physiology. It is worth ensuring that it is as effective as possible and that the body can regenerate as much as possible during sleep. Sleep disorders are caused by many factors related to our lifestyle. Sometimes it is difficult to diagnose sleep disorders, while they often overlap.
Sleep-related breathing disorders are connected with abnormal and difficult respiration during sleep. The influence of some of them on our health is small and of others huge. Modern technologies will make it possible to monitor sleep and its disturbances, depending on the severity. One thing is for sure, the correct amount of sleep allows us to feel and function better. It helps us to memory and attention restore and improvement.
This article is a joint work of Martyna Kaźmierczak (Faculty of Chemistry, University of Warsaw), Agnieszka Pregowska (Institute of Fundamental Technological Research, Polish Academy of Sciences) and Magdalena Osial (Faculty of Chemistry, University of Warsaw). Images Credit: Agnieszka Pregowska.
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