THE RISK OF DEATH GOES UP BY 15 PER CENT IF A PERSON SLEEPS FEWER THAN FOUR HOURS A NIGHT.

Sleep disorders do not affect only eye health. It is estimated that 30 per cent of other chronic diseases are also related to sleep issues. Clinical studies have shown that sleep deprivation affects brain function, said Dr Toh Song Tar. He is director of the sleep disorders unit and consultant in the department of otolaryngology at the Singapore General Hospital. When a person is sleepdeprived, it affects her thinking abilities and emotional states, Dr Toh said. The person cannot concentrate well, yawns frequently, and is generally more irritable than usual.

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Sleep disorders do not affect only eye health. It is estimated that 30 per cent of other chronic diseases are also related to sleep issues. Clinical studies have shown that sleep deprivation affects brain function, said Dr Toh Song Tar. He is director of the sleep disorders unit and consultant in the department of otolaryngology at the Singapore General Hospital. When a person is sleepdeprived, it affects her thinking abilities and emotional states, Dr Toh said. The person cannot concentrate well, yawns frequently, and is generally more irritable than usual.

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Lack of sleep also limits her ability to learn and affects her memory. When someone is sleep-deprived, the effects of alcohol consumption are magnified, as is her risk of being involved in an accident, added Dr Toh. A lack of sleep can also make a person shorttempered and subject to mood swings. Sleep deprivation can trigger mania episodes in people who have manic depression. Other risks include impulsive behaviour, depression, paranoia and suicidal thoughts.

Sleep deprivation can also cause micro-sleep. This is when she nods off for a few seconds – up to 30 – without realising it. This can be dangerous if the person is driving, said Dr Toh. Micro-sleep can also make a person more prone to injuries from trips and falls.

Studies show that sleep deprivation also weakens the body’s immune system, so a person falls sick more easily and recovers from illnesses more slowly than others.

If someone already has a chronic lung disease, sleep deprivation is likely to make it worse, said Dr Toh. Longterm sleep deprivation raises the risk of developing chronic conditions such as diabetes and cardiovascular diseases, he added.

Some studies have also found a link between lack of sleep and weight gain. Sleep deprivation increases the production of the stress hormone cortisol and lowers the levels of a hormone called leptin, which tells a person’s brain that she has had enough to eat. Weight gain leads to higher risks of chronic health problems such as high blood pressure, heart disease and stroke, said Dr Toh.

Overall, studies show that the risk of death from all causes goes up by 15 per cent if she sleeps fewer than four hours a night. Doctors should be aware of the harm that sleep disorders can cause.

Routine clinical examinations should include asking patients about their sleep, said Dr Toh. Snoring, for instance, is a sign of airway obstruction. It will cause damage to the upper airway tissue because of repetitive tissue trauma, leading to swelling and the tissue becoming more flaccid, he said. This will lead to the development of more obstruction and, eventually, obstructive sleep apnoea, which is the more common type of sleep apnoea.

A potentially serious sleep disorder, sleep apnoea is when breathing repeatedly stops and starts. Many people see the doctor only after they have been snoring for many years and, by then, the damage may have been done.

If she snores every night with choking, gasping episodes, has non-refreshing sleep and excessive daytime sleepiness, she should see a doctor for evaluation, said Dr Toh.

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