see also:

• stridor
• wheeze
• stertor
• obstructive sleep apnoea (OSA)
• physiology of sleep

• noise during breathing can be of various types depending upon whether awake or asleep and on where the airway obstruction arises
• snoring is a form of stertor which occurs during sleep either as a result of vibrations of nasopharyngeal structures with raised pharyngeal collapsibility or from nasal obstruction
• snoring may be inspiratory, expiratory or biphasic
• everyone snores occasionally
• habitual snoring affects over 40% of males and nearly a third of females aged 30-60yrs
• mild “snoring” can be from nasal obstruction and this noise can occur whilst awake and can be reproduced while awake by deep breathe through the nose when it is obstructed.
• loud snoring however is usually a result of vibrations of the upper airway structures which cannot be reproduced whilst awake and presumably has a neural component with loss of muscular tone of the upper airways during certain phases of sleep
• loud, habitual snoring may be severe enough to cause obstructive sleep apnoea (OSA) and excessive daytime sleepiness
• there is no good evidence to support snoring without obstructive sleep apnoea (OSA) is an independent risk factor for hypertension or cardiovascular disease

• snoring results from airflow-induced flutter of soft tissues of the nasopharynx, particularly the soft palate
• the fact that people do not snore while awake suggests that sleep-induced muscular relaxation is at least part of the aetiology because muscle tone is the only component of flutter that can change during sleep
• factors include:
  • upper airway obstruction
  • the mass, stiffness, and attachments of the fluttering element
  • the velocity and direction of airflow
    • local airflow velocity increases when the upper airway narrows (assuming inspiratory volume is maintained)

• arises within sleep especially in stages 3 and 4 from a vibration of soft tissue in the pharynx as inspired air flows down a partially occluded airway
• is unlikely in REM sleep as breathing as a rule is at its shallowest during this stage
• light snorers generally snore uniformly throughout all sleep stages
• heavy snorers tended to snore more during slow-wave and REM sleep and wakefulness time after sleep onset and sleep efficiency correlates significantly with the snoring index ¹⁾
• early in any history of snoring, an individual's pattern of snoring will be in part determined by the configuration of sleep staging across the night
• if respiratory weaknesses that underlie snoring develop, the individual may then cross a rubicon where the sleep pattern influences snoring less than it is influenced by the respiratory distress that gives rise to the snoring and normal sleep structure is undermined.

• see obstructive sleep apnoea (OSA)
• characterized by loud snoring followed by periods of silence when breathing stops or nearly stops which usually occurs at least five times during every hour of sleep
• snoring associated with sleep apnoea is least likely to occur in stages 3 & 4 (deep sleep) and is most likely in REM sleep
  • only when obstructive sleep apnoea becomes very severe and uniform throughout the night will deep non-REM stage 4 sleep be affected because light and REM sleep become so fragmented by apnoeas that the sufferer is not able to reach the point of descent into deep sleep, and it ceases to feature
• these apnoeas will splinter REM sleep with awakenings that permit the noisy recovery breaths and so start to erode the normal configuration of sleep staging across the night
• where REM alone is affected it can lead the sufferer to be chronically but specifically REM sleep deprived with a consequent propensity to fall into this particular state of sleep during the day otherwise, to fall from wakefulness directly to REM sleep is only normal in young babies
• sedatives may aggravate snoring associated with sleep apnoea by depressing the respiratory system, reducing deep non-REM sleep, and increasing light sleep at the expense of REM sleep.

• sleep-induced muscular relaxation of the soft palate muscles may cause²⁾:
  • reduced stiffness of the soft palate
  • increased upper airway obstruction and increased air velocity as a result of pharyngeal dilator muscles not being as active
  • risk of this is greater with:
    • alcohol within several hours of bedtime
    • sedatives, hypnotics and anxiolytics
• nasal obstruction including rhinitis, enlarged tonsils/adenoids, nasal septal deviation
  • alcohol and alpha adrenergic blockers also increase nasal congestion
  • chronic nocturnal nasal congestion is a 3-5x risk factor for habitual snoring ³⁾
• obesity and weight management
• hypothyroidism
• craniofacial abnormalities such as macroglossia, micrognathia or retrognathia, enlarged soft palate, enlarged lateral pharyngeal walls
• post-menopausal status
• pregnancy
• familial risk
• micrognathia
• predisposing anatomy of a narrowed oropharynx, such as a low-lying palate or redundant soft palate tissue, a thickened tongue base, or a narrow hypopharynx

• avoid alcohol and meals within several hours of bedtime
• avoid sedatives
• sleep with head elevated (NOT more pillows but raising the mattress itself)
• treat nasal congestion with nasal steroids, pseudoephedrine, etc as indicated
• if over-weight, then lose weight
• consider a light walk in the evening to reduce any retained leg swelling which may gravitate to the head on lying down
• exercises to strengthen the mouth, tongue, and throat:
  • tongue slide:
    • place the tip of your tongue against the back of your top front teeth.
    • slowly slide your tongue backward with the tip moving along the roof of your mouth and repeat 5-10 times.
  • tongue stretch:
    • push out your tongue as far as you can
    • try to touch your chin with your tongue while looking at the ceiling. Hold for 10 – 15 seconds and increase the duration gradually and repeat 5 times.
  • Tongue Push Up
    • push your tongue upward against the roof of your mouth and press your entire tongue against it. Hold this position for 10 seconds and repeat 5 times.
  • Tongue Push Down
    • put the tip of your tongue against your lower front teeth and then push the back of your tongue flat against the floor of your mouth. Hold this position for 10 seconds and repeat 5 times.
  • Cheek Hook
    • use a hooked finger to lightly pull your right cheek outward, and then use your facial muscles to pull your cheek back inward. Repeat 10 times on each side.
  • Lip purse:
    • tightly close your mouth by pursing your lips. Then open your mouth, relaxing your jaw and lips. Repeat 10 times.
  • Nose breathe:
    • alternate nose breathing by alternating blocking of each nostril
  • Vowel sounds:
    • repeat the vowel sounds a-e-i-o-u. Start by saying each normally, and then adjust how much you stretch out the sound or how rapidly you say the vowel. Repeat the same sound 10 or 20 times in a row, and then change to a different sound. You can combine sounds (such as ooo-aaah) and repeat those as well.
  • Singing:
    • try to focus on repeating and forcefully pronouncing individual sounds rather than just singing normal lyrics.
• domperidone (Motilium) 10mg nocte with nasal decongestant appears to be effective ⁴⁾
• assess for obstructive sleep apnoea (OSA) risk