Primary Snoring
Snoring is a condition characterized by noisy breathing during sleep. Usually, any medical condition where the normal airway is blocked during sleeping, like obstructive sleep apnea, gives rise to snoring. Snoring, when not associated with any such Obstructive phenomenon is known as Primary Snoring. Apart from the specific condition of Obstructive Sleep Apnoea, other causes of snoring include alcohol intake prior to sleeping, stuffy nose, sinusitis, obesity, long toungue or uvula, large tonsil or adenoid, smaller lower jaw, deviated nasal septum, asthma, smoking and sleeping on one's back. Primary Snoring is also known as Simple Snoring or Benign Snoring, and is not associated with sleep apnea, ie, temporary ceassation of breathing.
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Upper Airway Resistance Syndrome
Upper Airway Resistance Syndrome or UARS is a sleep disorder characterized by airway resistance to breathing during sleep. The primary symptoms include daytime sleepiness and excessive fatigue.
There is question in the medical community as to not only the existence of this syndrome, but whether it should be classified as a separate syndrome or part of the larger group Sleep-disordered Breathing (SDB). This unfortunately has led to a poor understanding of the illness by the medical community at large as well as a consequential lack of acceptance by medical facilities and health insurers.
It is difficult to confirm diagnosis, as few sleep testing centers have the proper test equipment to recognize the illness. Polysomnography (sleep study) with the use of a probe to measure Pes (esophageal pressure) is the gold standard diagnostic test for UARS. Apneas and hypopneas are absent or present in low numbers. Multiple snore arousals may be seen, and if an esophageal probe (Pes) is used, progressive elevation of esophageal pressure fluctuations terminating in arousals is noted. UARS can also be diagnosed using a nasal cannula/pressure transducer to measure the inspiratory airflow vs time signal.
During sleep the muscles of the airway become relaxed. The relaxation of these muscles in turn reduces the diameter of the airway. Typically, the airway of a UARS patient is already restricted or reduced in size, and this natural relaxation reduces the airway further. Therefore, breathing becomes labored. It can be likened to breathing through a coffee straw.
Pathophysiology of UARS is similar to obstructive sleep apnea / hypopnea syndrome in that abnormal airway resistance in the upper airway during sleep leads to unwanted physiologic consequences. Increased upper airway resistance in this disorder does not lead to cessation of airflow (apnea) or decrease in airflow (hypopnea), but instead leads to an arousal secondary to increased work of breathing to overcome the resistance. Repeated and multiple arousals (which the patient is usually unaware of) result in an abnormal sleep architecture and daytime somnolence (sleepiness). Arousals result in sympathetic activation, and UARS is therefore likely to cause hypertension similar to obstructive sleep apnea syndrome (This has not been verified in large clinical populations because of the relatively small number of patients with UARS in the larger epidemiologic studies so far. However, repeated arousals in individuals have clearly been shown to be related to sympathetic activation and elevation in blood pressure.)
Patients present with snoring and excessive daytime somnolence. Hypotension is likely to be present. Also, fatigue, cognitive impairment, unrefreshing sleep, frequent awakenings, and chronic pain may be present. UARS is often misdiagnosed as Fibromyalgia or similar disorders. Guilleminault et al. write that up to 75% of adult patients with sleepwalking have UARS.
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Sleep Apnea
Sleep apnea (or sleep apnoea in British English) is a sleep disorder characterised by having one or more pauses in breathing or shallow breaths during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or a "sleep study".
There are three distinct forms of sleep apnea: central, obstructive, and complex (i.e., a combination of central and obstructive) constituting 0.4%, 84% and 15% of cases respectively. Breathing is interrupted by the lack of respiratory effort in central sleep apnea; in obstructive sleep apnea, breathing is interrupted by a physical block to airflow despite respiratory effort. In complex (or "mixed") sleep apnea, there is a transition from central to obstructive features during the events themselves.
Regardless of type, the individual with sleep apnea is rarely aware of having difficulty breathing, even upon awakening. Sleep apnea is recognized as a problem by others witnessing the individual during episodes or is suspected because of its effects on the body (sequelae). Symptoms may be present for years (or even decades) without identification, during which time the sufferer may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance.
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Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is a common sleep apnea caused by obstruction of the airway. It is characterized by pauses in breathing during sleep. These episodes, called apneas (literally, "without breath"), each last long enough that one or more breaths are missed, and occur repeatedly throughout sleep. In obstructive sleep apnea, breathing is interrupted by a physical block to airflow, despite the effort to breathe.
The individual with sleep apnea is rarely aware of having difficulty breathing, even upon awakening. Sleep apnea is recognized as a problem by others witnessing the individual during episodes or is suspected because of its effects on the body (sequelae).
Symptoms may be present for years, even decades without identification, during which time the sufferer may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance. Persons who sleep alone without a long-term human partner may not be told about their sleep disorder symptoms.
Since the muscle tone of the body ordinarily relaxes during sleep, and since, at the level of the throat, the human airway is composed of walls of soft tissue, which can collapse, it is easy to understand how breathing can be obstructed during sleep. Although a very low level of obstructive sleep apnea is considered to be within the bounds of normal sleep, and many individuals experience episodes of obstructive sleep apnea at some point in life, a much smaller percentage of people are afflicted with chronic, severe obstructive sleep apnea.
Many people experience episodes of obstructive sleep apnea for only a short period of time. This can be the result of an upper respiratory infection that causes nasal congestion, along with swelling of the throat, or tonsillitis that temporarily produces very enlarged tonsils. The Epstein-Barr virus, for example, is known to be able to dramatically increase the size of lymphoid tissue during acute infection, and obstructive sleep apnea is fairly common in acute cases of severe infectious mononucleosis. Temporary spells of obstructive sleep apnea syndrome may also occur in individuals who are under the influence of a drug (such as alcohol) that may relax their body tone excessively and interfere with normal arousal from sleep mechanisms.
