The Snoring Mechanism During sleep, all the muscles of the body become less active and are relaxed and even floppy. In most parts of the body this does not matter and indeed helps one to relax and sleep comfortably. However, the floppy segment of the airway between the back of the nose and the entrance to the voice box (larynx) including the throat (pharynx) gets affected too. When the muscles behind the tongue that help hold the throat open relax, there is partial collapse and narrowing of the airway resulting in vibrations which are heard as a 'snore'. The noise is generated by the curtain-like soft palate at the level of the roof of the mouth (flutter) or by the back of the tongue, or both. Obstructive Sleep Apnoea If the 'floppy segment' does not vibrate but collapses and locks off the airway instead, breathing is stopped for a variable period of time (few seconds). This is termed 'Obstructive Sleep Apnoea' (OSA). People who have this condition usually are big snorers. Apnoea refers to the actual stoppage of breathing. Fortunately, the body is able to sense this increased obstruction to breathing and the sufferer wakes briefly, takes a few deep breaths and rapidly returns to sleep. This obstruction and waking may become a continuous cycle that can go on several times each night. Health Hazards of OSA OSA can damage your health as it reduces the amount of oxygen in the blood. You may not be aware of the number of times that your sleep is disturbed because of these apnoeic episodes. In the morning you are likely to feel extremely tired, and you may tend to nod off frequently during the day. This is termed 'excessive daytime somnolence (sleepiness)'. In the beginning, this occurs only during potentially boring activities such as reading, watching television or long distance driving on the motorways. Not only is this a nuisance, but this may also become a dangerous issue, especially if you are driving regularly, or if you work with machinery (sleep apnoea sufferers are about seven times more likely to have car accidents). OSA can also affect the heart as this can raise the blood pressure and cause abnormalities of the heart rhythm, and in severe cases, congestive cardiac failure.