She walked into my room, sat down and said: "'Doc, you have to help me. I haven't slept well in four months. I've tried everything and nothing has worked."
Madam S had stopped drinking coffee and alcohol, and tried taking herbal supplements bought from the pharmacy.
She had bought a new pillow and asked her husband to sleep in the other room. She was turning 70 and was looking forward to enjoying her retirement.
She was quite distressed over having sleepless nights, which affected her daytime activities.
She had stopped doing taiji every morning and couldn't spend quality time with her grandchildren as she was too tired.
I asked her about her sleep environment, daily routine, medical history, family background and how she coped with stress.
She was surprised by the numerous questions and wondered how her answers would help.
I explained that our ability to fall asleep depended on the interplay of physical and psychological factors.
Up to one in three people experiences transient insomnia and one in 10 suffers from chronic insomnia. People with transient insomnia tend to experience at least one night of difficulty falling asleep, which resolves within the week.
On the other hand, chronic insomnia sets in if it lasts for longer than three months.
A study conducted in 2007 found that almost half of the patients who visited a sleep clinic in Singapore had primary insomnia, which is difficulty sleeping for no apparent reason, while a quarter suffered from insomnia secondary to anxiety disorders, with a tenth afflicted with insomnia as a result of depression.
The international classification of sleep disorders defines insomnia as having difficulty falling asleep, staying asleep or waking up before the desired time that occur at least three nights a week for three months.
This is associated with not being able to function well during the day.
At this point, most people would start to seek medical attention.
As people age, sleep efficiency generally deteriorates, resulting in more dissatisfaction with sleep.
In older people, sleep may be disturbed by the urge to urinate frequently at night, which may be the result of a urinary condition.
Heart or lung problems are common in older people who may experience breathlessness or discomfort when lying down, affecting their ability to sleep soundly.
Chronic pain and a multitude of prescription medications may further exacerbate insomnia.
In these instances, addressing the root cause of difficulty in sleeping is the recommended first line of treatment, such as minimising pain and discomfort.
Even though Madam S was not suffering from anxiety or depression, she was sufficiently distressed by her insomnia to think that life was not worth living.
Tossing and turning in bed every night was not the solution, especially when she experienced fatigue during the daytime.
This affected her ability to carry out her daily chores or even to properly enjoy life. She was also worried that sleeping poorly would affect her health.
Her concerns were not unfounded.
Insomnia is associated with a higher rate of heart disease, hypertension and diabetes, and has been linked to the development of dementia in later life.
I advised her on how she could make adjustments to sleep better.
•Sleeping environment: It should be conducive for rest. A dark, quiet and uncluttered room, comfortable bedding and a comfortable temperature will help her sleep better.
•Stimulating substances and activities: Avoid them near bedtime. Exercise four hours before bedtime is discouraged as the adrenaline rush will keep her awake.
•Caffeinated drinks: They should not be consumed near bedtime as caffeine can remain in the bloodstream for up to 12 hours.
•Alcohol: Although it may cause drowsiness, it interferes with the normal sleep process, causing frequent interruptions and poor sleep quality.
•Sleeping and waking: I encouraged Madam S to do this at the same time every day, even on weekends.
•Set the tone: A warm shower, light reading and calming soft music can help one get a good night's sleep.
•Avoid daytime naps: This was one of the hardest things for Madam S to do as she had to lie down after lunch every day due to back pain and would inevitably doze off for a few minutes.
We also discussed the use of medications for sleep. Sleeping pills such as benzodiazepines are commonly prescribed to treat insomnia in the short term.
But there is a risk of tolerance and dependence, which can lead to a need for higher doses.
Side effects such as drowsiness and being over-sedated in the day frequently contribute to memory impairment and falls in older people.
Other medications that can be considered are anti-histamines, anti-depressants and anti-psychotic medication.
Alternative treatments such as acupuncture, melatonin and herbal preparations have been reported to be helpful to varying degrees for those suffering from insomnia, but medical evidence supporting their use has not been very robust.
Non-medicinal therapies to treat insomnia include relaxation training, stimulus control and cognitive behavioural therapy for insomnia.
These involve learning techniques to relax the mind and body, building a positive association between the bedroom and sleep, as well as addressing thoughts and behaviours that underlie and drive a person's sleep problems.
A therapist, usually a psychologist, can help with these over a few sessions.
Madam S agreed to a short course of sleeping pills, while modifying her sleep habits at the same time.
She was more upbeat the next time she saw me. She had managed to kick the habit of napping after lunch, switching her afternoon tea to a non-caffeinated drink, and also started to brisk walk in the morning.
She eventually managed to sleep without medication. Making small changes to her lifestyle helped her sleep better and she was happy to be able to function as before.
•Dr Sin is a consultant in the department of psychiatry at the Singapore General Hospital.