In accordance to the Dorland’s Medical Dictionary for Health Consumers, consciousness is “the state of awareness of our own feeling, thoughts, and sensations, being fully aware, oriented and responsive to the environment”. There are various levels of awareness that we experience each and every day, some occurring concurrently. Low awareness entails the evaluation of sensory stimuli such as smells, sight, and sounds (Diener " Teeny, n.d.). In this state, there is in constant awareness of the surrounding, however, we do not recognize each and every detail. A number of sensory stimuli elicit a response automatically without us being aware. For example, when we are in fear, we automatically either start sweating or become numb without the body’s physical output. This shows a sense of low awareness.
High awareness is yet another state of consciousness, which includes high attention, alertness and careful decision making. A good example of high awareness is mindfulness which is the ability to fathom the thoughts and experiences that cross our minds. Meditation is also an aspect of high awareness that includes strict attention and focuses on a particular thing or state of being. Human beings alternate between high and low awareness states to achieve an optimal state of consciousness.
Hypnosis is characterized by a reduction in peripheral stimulation and awareness with increased attention to a particular single stimulus (Kihlstrom, 2003). It is a state of awareness that is in between high and low awareness whereby an individual forgets his/her surrounding and the feelings elicited by the environment and is at the power of the hypnotist. The hypnotist can control the reactions, actions, movements and the general mood of the subject under hypnosis. Evidence suggests that this altered state of consciousness can be beneficial in surgery in patients who are allergic to anesthesia. The patients are hypnotized and the stimuli of pain removed.
Sleep is a state of consciousness that lacks full awareness of the surrounding but the brain is fully active. Sleep is proven to be a state of consciousness due to the brain waves that can be observed during sleep. During states of active brain functionality i.e. when we are awake and alert, the predominant brain waves are beta waves which are high in frequency but low in intensity (Diener " Teeny, n.d.). In a relaxed state, alpha waves are predominant which point out to a state of reducing frequency and consistent brain activity (Diener " Teeny, n.d.). These two waves in combination with theta waves are seen in sleep, alternating between the various stages of sleep. There are four stages of sleep namely Non-Rapid Eye Movement (NREM) 1, NREM 2, NREM 3 and the final stage being REM stage. NREM 1 is the stage where one falls asleep. Theta waves are predominant in this stage. Stage 2, NREM2, occurs immediately after NREM 1 and is considered as light sleep and it is associated with memory processing. NREM 3 is associated with muscle relaxation and finally, Random Eye Movement Stage (REM) is associated with dreaming. This stage, in terms of brain activity, resembles a state of wakefulness (Diener " Teeny, n.d.).
Disorders associated with disturbances of either stage of sleep, metabolic, physical, mental and psychological disorders contribute to disorders in sleep and the circadian rhythm that regulates our sleep-wake cycles. Sleep apnea, insomnia, sleepwalking, and sleep terrors are a number of examples of sleep disorders that are discussed below.
Sleep Apnea
Sleep Apnea is described as the interruption of breathing during sleep that occurs repeatedly leading to frequent interruption of sleep as one wakes up to try and breath. Oxygen levels in the brain are reduced, which signals the body to wake up. There are two types of sleep apnea namely obstructive sleep apnea (OSA) and Central Sleep Apnea (CSA).
OSA is caused by the blockage of the respiratory tract airway leading to upper airway collapse (Downey, 2018) during sleep which leads to frequent arousal from sleep (Downey, 2018). The signs and symptoms of OSA include; loud habitual snoring, a choking sensation that leads to waking up, inability to sleep, and excessive urination at night. During the day, common symptoms include a headache, waking up tired (Nornrestorative sleep), daytime sleepiness that is excessive and frequent, excessive fatigue, short-term memory loss, lowered libido and sexual dysfunction, reduced vigilance and hypertension.
The causes of OSA can be divided into structural factors, nonstructural factors, and genetic factors. Structural factors relate to deformities or syndromes that may lead to obstruction of the respiratory tract. Anatomical variations such as facial elongation have been seen to cause OSA. Nasal obstructions such as nasal polyps and stenosis (Narrowing of the nasal canal) predispose people to OSA since they block the airflow, especially during sleep. A blockage of the airflow leads to sleep apnea. Patients with Down syndrome are also prone to sleep apnea due to craniofacial abnormalities such as a shortened nose, flat nasal bridge, and protruding tongue. Nonstructural factors that increase the risk to OSA include, obesity, male sex, and smoking, lying on the back (supine sleeping position), alcohol use and age-related factors. In children tonsils play a significant role in sleep apnea, leading to the blockage of the throat.
The most common predisposing factors are obesity and smoking. Obesity increases the general body mass and the amount of soft tissue in the mouth and throat which block the airways during sleep (Blahd, 2016). This blockage is as a result of a relaxed muscular state that is associated with sleep. The blockage leads to choking and gasping for air, forcing one to wake up. Smoking contains particles that activate the immune system leading to the inflammation of the respiratory system (Krishnan, Williams, " Thornton, 2014). This inflammation blocks the upper respiratory system predisposing an individual to sleep apnea.
Central Sleep apnea is as a result of defective respiratory control center leading to a lack of signaling mechanism of the respiratory muscles (Downey, 2018). It is a rare sleeping condition and mainly caused by medical conditions such as strike, Diabetes mellitus, hypothyroidism acromegaly and Myasthenia Gravis.
Sleep apnea may lead to stroke, hypertension, diabetes, migraines, depression and heart failure. Physical activities may also be impaired such as poor work performance and poor coordination which may lead to various hazards such as vehicle accidents. Management of sleep apnea is thus paramount to prevent the above complications. Management basically depends on the etiology. Treatment of the underlying causative agent leads to improvement of sleep.
Insomnia
Insomnia is the difficulty and inability to sleep, that can either be acute or chronic. Acute insomnia is the inability to sleep at any given time over a short period of time whereas chronic insomnia is a prolonged difficulty, disturbed and disrupted sleep that has an occurrence of over three nights per week for at least three months. Individual with insomnia experience a difficulty in the onset and maintenance of sleep (Roth, 2007) and may lead to gross health and physical complications.
The causative agents for insomnia can be divided into medical and psychological causes that disrupt sleep. The medical condition that can lead to insomnia include; sinus allergies, Gastroesophageal reflux (heartburn), hyperthyroidism, asthma, pain, and sleep apnea. Chronic pain is a major causative agent whereby the patient is in excessive pain which disrupts the onset of sleep and it can also lead to disturbed sleep. A number of medications taken for hypertension, depression common cold and birth control drugs may cause insomnia as a side effect. Sleep apnea, a sleeping disorder on its own may lead to insomnia. The experience of lack of breath during sleep may lead to a state of hyper-vigilance and fear thus leading to insomnia.
Psychiatric conditions such as depression and anxiety may cause insomnia. The altered mental status brought about by depression is responsible for insomnia. In depression, an individual is worried and stressed with a lot of thoughts. These thoughts and worry keep the brain in an active state, preventing the initiation of sleep (Roth, 2007). Worry itself and stress without depression can also independently lead to insomnia (National Sleep Foundation).
Insomnia is associated with poor quality of life and reduced performance due to fatigue to affects daily performance. Sleep is required to rejuvenate the body hence a lack of it leads to a state of constant fatigue. Insomnia itself may also lead to depression and other psychiatric conditions. The management includes treatment of the underlying condition, for example, treatment of depression, chronic, sleep apnea and administration of sleeping drugs
Sleepwalking
Sleepwalking is scientifically known as somnambulism, which is a disorder associated with a motor activity such as walking during sleep (Mahowald, n.d.) and mainly affects children. There is a relationship between sleepwalking and psychological/psychiatric factors with triggers being sleep deprivation, fever and febrile conditions, alcohol and other sedative agents and certain medications (Mahowald, n.d.). It mainly occurs during REM sleep signifying an association with dreaming. In children, the condition is resolved once they grow older, however, in adults hypnosis has been shown to reduce the incidences of sleepwalking. Various pharmacological agents such as antidepressants and sedatives have been used in treatment, however, there is no definitive pharmacological treatment for sleepwalking,
Narcolepsy
Narcolepsy is a sleeping disorder characterized by daytime sleepiness, sudden onset drowsiness, and hallucination. The sleepiness is sudden and it can be associated with muscle weakness and inability to control muscles (Dauvilliers, 2008). The exact etiology is unknown however a deficiency in the neurochemical hypocreptin has been hypothesized as the etiology. Hypocreptin regulates sleep and wakefulness state thus a deficiency would lead to lack of coordination. There is no definitive cure for narcolepsy however stimulants are the primary mode of treatment. Stimulants activate the brain reducing the chances to fall asleep.
References
References
Blahd, W. (2016). Sleep Apnea. WebMD.
Dauvilliers, Y. (2008). Narcolepsy with cataplexy. Pubmed.
Diener, R., " Teeny, J. (n.d.). States of Consciousness. NOBA.
Downey, R. (2018). Obstructive Sleep Apnea. Medscape.
Evans, K. (2009). Understanding Consciousness Part 1. NaturalNews.
Kihlstrom, J. (2003). Hypnosis and Memory. Learning and Memory, 240-242.
Krishnan, V., Williams, S., " Thornton, D. (2014). Where There is Smoke. There is Sleep Apnea. American College of Chest Physicians, 1673-1680.
Mahowald, M. (n.d.). Sleep Walking. National Sleep Foundation.
National Sleep Foundation. (n.d.). What Causes Insomnia. national Sleep foundation.
Roth, T. (2007). Insomnia: Definition, Prevalence, Etiology, and Consequences. Journal of Clinical Sleep Medicine, 7-9.
