Sleep should be a quiet affair, but if you or your bed partner snores, the harsh sounds can keep you up at night.
Snoring happens when there's an increased resistance to the flow of air during breathing. This causes the structures in your oral cavity to vibrate.
The strange thing is, it appears to be a product of human evolution.
Dr Kenny Pang, an ear, nose, throat specialist at Asia Sleep Centre at Paragon, said that based on Darwin's theory of evolution, when a four-legged animal evolved to stand on two legs, bodily changes occur.
First, the diameter of the head grew smaller. The face and neck also elongated upwards, so the airway is no longer protected by the skeleton.
With the airway now surrounded by skin, muscles and soft tissues, Dr Pang said it is more vulnerable to collapsing, injury and trauma. That is why snoring and obstructive sleep apnoea are more common in humans compared to animals.
More than half who snore are afflicted by obstructive sleep apnoea, when breathing repeatedly stops and starts during sleep.
Dr Pang and Dr Mahesh Babu Ramamurthy, head and senior consultant at National University Hospital's division of paediatric pulmonary and sleep, tell us five signs of abnormal snoring:
1. Frequency of snoring
People may snore when they are sick or very tired. The common cold or the more serious influenza may result in snoring from the mouth or nose. This is because of vibrating phlegm at the back of the throat or in the nose.
Yet, a habitual snorer- someone who snores on more than four nights in a week- can experience some long-term effects.
2. Loudness of snores
Loud snoring, especially if it can be heard from outside the room, indicates a more severe degree of obstruction in the airway. However, the loudness of one's snores does not indicate the severity of obstructive sleep apnoea.
3. Snoring pattern
Snoring can either be continuous or intermittent - when the observer can hear pauses in the sleeper's breathing. These pauses indicate severe obstruction and temporary blockage of air from entering the lungs. This results in less oxygen being delivered to the body.
4. Snoring in different positions
Snoring is more likely to occur when you lie flat on your back. Here, the tongue falls backwards due to gravity to block the airway. It is why changing a person's sleep position can often stop his snoring. But if the snoring persists even after the sleeper turns on his side or sleeps sitting up, raise the alert with a doctor.
5. Other symptoms
If the snorer is sweating even in an air-conditioned rooms, it indicates that he is working hard to breathe properly. Other symptoms related to obstructive sleep apnoea include daytime sleepiness or tiredness, poor concentration, headaches, a dry or sore throat in the morning and a choking sensation at night.
Learn how to combat obstructive sleep apnoea, which is on the rise, in the latest issue of Mind Your Body, which comes with The Straits Times every Thursday.