The average person spends about six to eight hours per day sleeping.
This works out to each person sleeping for about one-third of the day.
Yet, so many of us take sleep for granted.
The average Singaporean who lives up to about 80 years old (the current life expectancy), will spend 26 years of his life sleeping.
It is well accepted that dream sleep (25 per cent of sleep) is the most important element in the sleep process for well being, memory rebuilding, rejuvenation and mental alertness.
It is vital to the human mind and body.
Simplistically, dream sleep is defined as having a highly active brain in a "paralysed" body.
This is to prevent us from acting out our dreams.
So if one were to dream that one was playing football, one does not actually kick and act it out in bed, endangering one's bed partner.
This, however, works against a patient with a narrowed airway (narrow throat or air conduit).
The already narrowed airway will lose its tone during dream sleep as it completely relaxes and collapses, leading to upper airway obstruction, cessation of breathing and lack of oxygen.
Therefore, this leads to stress on the heart, brain and other organs in the body.
The dream sleep component of sleep is crucial for memory rebuilding, rejuvenation and well being. It will not be able to take place if the body is deprived of oxygen, due to a stoppage in breathing, resulting from a blocked airway.
This results in interrupted sleep, sleep fragmentation and poor sleep quality.
During the day, the person will be excessively sleepy, have poor concentration, poor memory and be irritable and moody.
Common patient complaints include early morning tiredness and morning headaches.
Other symptoms include forgetfulness, depression, irritability and less commonly, impotence.
During the night, patients may complain of frequent awakening with a choking and gasping sensation, frequent passing of urine or nightmares.
Many bed partners have witnessed their partners choking and holding their breath during their sleep. This is obstructive sleep apnoea.
Long-term health consequences include high blood pressure, heart disease, strokes and sudden death during sleep.
It affects about 15 per cent of people here.
One such person is Mr Jimmy Ang.
For a few years, the 55-year-old snored loudly during his sleep and felt very tired the next day despite sleeping an adequate number of hours. He was not overweight but his lower jaw was small his tongue was quite big.
He also suffered from high blood pressure, which was aggravated by his interrupted sleep. The recurrent halting of breathing and low oxygen intake at night resulted in nocturnal high blood pressure and eventual day-time hypertension.
His wife would observe him choking and gasping for breath during the night while he slept.
He said his "wake-up" call came when he fell asleep while driving in the afternoon and hit another vehicle in front.
He did a test - a home-based, wrist-worn sleep test in 2009, which confirmed that he was suffering from severe obstructive sleep apnoea.
A few months later, he had nose, palate and tongue surgery.
Since the surgery, his life has changed for the better. His nose passages feel opened, his breathing is very smooth and he does not snore any more.
He is able to breathe without difficulty in his sleep and feels refreshed in the mornings. His high blood pressure is now very well controlled.
He was so happy with his surgery that he sent his 19-year-old son for the same surgery. His son also suffered from poor quality sleep and snoring.
But not every one needs surgery.
Roughly about half the patients I see will benefit from it.
Surgery depends on the anatomy in the patient's nose and mouth. It also depends on the age of the patient and other medical issues that the patient might have.
Non-surgical treatments include weight loss, sleeping on one's side and continuous positive airway pressure (CPAP) therapy.
CPAP is a treatment that delivers slightly pressurised air during the breathing cycle which keeps the windpipe open during sleep and prevents episodes of blocked breathing in persons with obstructive sleep apnoea and other breathing problems.
Man's sleep apnoea has much to do with evolution.
From the four-legged crawling canines to the two-legged standing gorillas, the airway is structurally within the cranio-facial skeleton (solid hard box/skull) of the animal.
Based on Darwin's theory of evolution, it is well-known that as the four-legged animal evolved and stood up, many changes took place in the upper body, namely, the upper limbs (arms/hands) got shorter, the spine became stronger, firmer and upright, the brain became bigger and, most crucially, the face shape also changed.
As the face shape changed and became shorter from front to back, the face grew longer, the upper head expanded (as the brain grew bigger), and neck development also increased.
As the neck gradually grew longer, the airway conduit was no longer protected by the cranio-facial skeleton.
The unprotected airway in the neck is now surrounded by skin, muscles and soft tissues.
It is more vulnerable and prone to collapse, injury and trauma.
This leads to a much higher incidence of snoring and obstructive sleep apnoea in humans compared with animals.
So do not lose any more sleep. If you have a snoring problem and feel tired during the day despite having "slept" enough hours, get help.
Dr Kenny Peter Pang is an ear, nose and throat and sleep specialist at the Asia Sleep Centre at Paragon
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